21679056 has 160 divisors (see below), whose sum is σ = 72852480. Its totient is φ = 6044544.

The previous prime is 21679051. The next prime is 21679081. The reversal of 21679056 is 65097612.

21679056 = 130³ + 131³ + ... + 138³.

It is a super-2 number, since 2×21679056² = 939962938102272, which contains 22 as substring.

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 21679056.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21679051) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 202555 + ... + 202661.

It is an arithmetic number, because the mean of its divisors is an integer number (455328).

Almost surely, 2^21679056 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21679056, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36426240).

21679056 is an abundant number, since it is smaller than the sum of its proper divisors (51173424).

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

21679056 is a wasteful number, since it uses less digits than its factorization.

21679056 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 198 (or 186 counting only the distinct ones).

The product of its (nonzero) digits is 22680, while the sum is 36.

The square root of 21679056 is about 4656.0773189456. The cubic root of 21679056 is about 278.8346806477.

The spelling of 21679056 in words is "twenty-one million, six hundred seventy-nine thousand, fifty-six".