21285016 has 32 divisors (see below), whose sum is σ = 42260400. Its totient is φ = 10022400.

The previous prime is 21285013. The next prime is 21285023. The reversal of 21285016 is 61058212.

It is a super-2 number, since 2×21285016² = 906103812240512, which contains 22 as substring.

21285016 is a modest number, since divided by 5016 gives 2128 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21285013) 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, 35116 + ... + 35716.

Almost surely, 2^21285016 is an apocalyptic number.

It is an amenable number.

21285016 is a deficient number, since it is larger than the sum of its proper divisors (20975384).

21285016 is a wasteful number, since it uses less digits than its factorization.

21285016 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 859 (or 855 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 25.

The square root of 21285016 is about 4613.5686837848. The cubic root of 21285016 is about 277.1349679164.

The spelling of 21285016 in words is "twenty-one million, two hundred eighty-five thousand, sixteen".