27720000 has 420 divisors, whose sum is σ = 123785376. Its totient is φ = 5760000.

The previous prime is 27719999. The next prime is 27720001. The reversal of 27720000 is 2772.

It is an interprime number because it is at equal distance from previous prime (27719999) and next prime (27720001).

It is a tau number, because it is divible by the number of its divisors (420).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a super Niven number, because it is divisible the sum of any subset of its (nonzero) digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (27720001) by changing a digit.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 2519995 + ... + 2520005.

Almost surely, 2^27720000 is an apocalyptic number.

27720000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 27720000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (61892688).

27720000 is an abundant number, since it is smaller than the sum of its proper divisors (96065376).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

27720000 is a wasteful number, since it uses less digits than its factorization.

27720000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56 (or 28 counting only the distinct ones).

The product of its (nonzero) digits is 196, while the sum is 18.

The square root of 27720000 is about 5264.9786324353. The cubic root of 27720000 is about 302.6433080056.

Adding to 27720000 its reverse (2772), we get a palindrome (27722772).

Multiplying 27720000 by its reverse (2772), we get a square (76839840000 = 277200²).

27720000 divided by its reverse (2772) gives a 4-th power (10000 = 10⁴).

It can be divided in two parts, 27 and 720000, that added together give a palindrome (720027).

The spelling of 27720000 in words is "twenty-seven million, seven hundred twenty thousand".