21632985 has 72 divisors (see below), whose sum is σ = 42948360. Its totient is φ = 10053120.

The previous prime is 21632983. The next prime is 21633011. The reversal of 21632985 is 58923612.

It can be written as a sum of positive squares in 4 ways, for example, as 2944656 + 18688329 = 1716^2 + 4323^2 .

It is not a de Polignac number, because 21632985 - 2¹ = 21632983 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is not an unprimeable number, because it can be changed into a prime (21632983) 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 71 ways as a sum of consecutive naturals, for example, 157837 + ... + 157973.

It is an arithmetic number, because the mean of its divisors is an integer number (596505).

Almost surely, 2^21632985 is an apocalyptic number.

It is an amenable number.

21632985 is a deficient number, since it is larger than the sum of its proper divisors (21315375).

21632985 is a wasteful number, since it uses less digits than its factorization.

21632985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 199 (or 185 counting only the distinct ones).

The product of its digits is 25920, while the sum is 36.

The square root of 21632985 is about 4651.1272827133. The cubic root of 21632985 is about 278.6370197762.

The spelling of 21632985 in words is "twenty-one million, six hundred thirty-two thousand, nine hundred eighty-five".