21727656 has 32 divisors (see below), whose sum is σ = 60355200. Its totient is φ = 7242480.

The previous prime is 21727639. The next prime is 21727661. The reversal of 21727656 is 65672712.

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

It is a self number, because there is not a number n which added to its sum of digits gives 21727656.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 50080 + ... + 50511.

It is an arithmetic number, because the mean of its divisors is an integer number (1886100).

Almost surely, 2^21727656 is an apocalyptic number.

It is an amenable number.

21727656 is an abundant number, since it is smaller than the sum of its proper divisors (38627544).

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

21727656 is a wasteful number, since it uses less digits than its factorization.

21727656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 100606 (or 100596 counting only the distinct ones).

The product of its digits is 35280, while the sum is 36.

The square root of 21727656 is about 4661.2933827426. The cubic root of 21727656 is about 279.0428885391.

The spelling of 21727656 in words is "twenty-one million, seven hundred twenty-seven thousand, six hundred fifty-six".