21487056 has 40 divisors (see below), whose sum is σ = 55770240. Its totient is φ = 7128576.

The previous prime is 21487051. The next prime is 21487079. The reversal of 21487056 is 65078412.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21487051) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10536 + ... + 12408.

It is an arithmetic number, because the mean of its divisors is an integer number (1394256).

Almost surely, 2^21487056 is an apocalyptic number.

It is an amenable number.

21487056 is an abundant number, since it is smaller than the sum of its proper divisors (34283184).

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

21487056 is a wasteful number, since it uses less digits than its factorization.

21487056 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2123 (or 2117 counting only the distinct ones).

The product of its (nonzero) digits is 13440, while the sum is 33.

The square root of 21487056 is about 4635.4132501860. The cubic root of 21487056 is about 278.0090744584.

The spelling of 21487056 in words is "twenty-one million, four hundred eighty-seven thousand, fifty-six".