21122985 has 32 divisors (see below), whose sum is σ = 36691200. Its totient is φ = 10315008.

The previous prime is 21122971. The next prime is 21123013. The reversal of 21122985 is 58922112.

It is not a de Polignac number, because 21122985 - 2⁶ = 21122921 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 28692 + ... + 29418.

It is an arithmetic number, because the mean of its divisors is an integer number (1146600).

Almost surely, 2^21122985 is an apocalyptic number.

It is an amenable number.

21122985 is a deficient number, since it is larger than the sum of its proper divisors (15568215).

21122985 is a wasteful number, since it uses less digits than its factorization.

21122985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 897.

The product of its digits is 2880, while the sum is 30.

The square root of 21122985 is about 4595.9748693830. The cubic root of 21122985 is about 276.4299510702.

The spelling of 21122985 in words is "twenty-one million, one hundred twenty-two thousand, nine hundred eighty-five".