27721020 has 48 divisors (see below), whose sum is σ = 78694560. Its totient is φ = 7289856.

The previous prime is 27721009. The next prime is 27721039. The reversal of 27721020 is 2012772.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1216 + ... + 7544.

It is an arithmetic number, because the mean of its divisors is an integer number (1639470).

Almost surely, 2^27721020 is an apocalyptic number.

27721020 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 27721020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39347280).

27721020 is an abundant number, since it is smaller than the sum of its proper divisors (50973540).

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

27721020 is a wasteful number, since it uses less digits than its factorization.

27721020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6414 (or 6412 counting only the distinct ones).

The product of its (nonzero) digits is 392, while the sum is 21.

The square root of 27721020 is about 5265.0754980342. The cubic root of 27721020 is about 302.6470200353.

Adding to 27721020 its reverse (2012772), we get a palindrome (29733792).

The spelling of 27721020 in words is "twenty-seven million, seven hundred twenty-one thousand, twenty".