21556948 has 24 divisors (see below), whose sum is σ = 43848000. Its totient is φ = 9081408.

The previous prime is 21556943. The next prime is 21556961. The reversal of 21556948 is 84965512.

It is a hoax number, since the sum of its digits (40) coincides with the sum of the digits of its distinct prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 21556948.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21556943) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4873 + ... + 8176.

It is an arithmetic number, because the mean of its divisors is an integer number (1827000).

Almost surely, 2^21556948 is an apocalyptic number.

21556948 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21556948 is an abundant number, since it is smaller than the sum of its proper divisors (22291052).

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

21556948 is a wasteful number, since it uses less digits than its factorization.

21556948 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13119 (or 13117 counting only the distinct ones).

The product of its digits is 86400, while the sum is 40.

The square root of 21556948 is about 4642.9460475004. The cubic root of 21556948 is about 278.3101794676.

The spelling of 21556948 in words is "twenty-one million, five hundred fifty-six thousand, nine hundred forty-eight".