27728640 has 216 divisors, whose sum is σ = 100442160. Its totient is φ = 7053312.

The previous prime is 27728633. The next prime is 27728647. The reversal of 27728640 is 4682772.

27728640 is a `hidden beast` number, since 2 + 7 + 7 + 2 + 8 + 640 = 666.

It is an interprime number because it is at equal distance from previous prime (27728633) and next prime (27728647).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 27728595 and 27728604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (27728647) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 334039 + ... + 334121.

It is an arithmetic number, because the mean of its divisors is an integer number (465010).

Almost surely, 2^27728640 is an apocalyptic number.

27728640 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 27728640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (50221080).

27728640 is an abundant number, since it is smaller than the sum of its proper divisors (72713520).

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

27728640 is a wasteful number, since it uses less digits than its factorization.

27728640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 139 (or 122 counting only the distinct ones).

The product of its (nonzero) digits is 37632, while the sum is 36.

The square root of 27728640 is about 5265.7990846594. The cubic root of 27728640 is about 302.6747481999.

The spelling of 27728640 in words is "twenty-seven million, seven hundred twenty-eight thousand, six hundred forty".