21633287890825 has 12 divisors (see below), whose sum is σ = 28888759830028. Its totient is φ = 15975351057600.

The previous prime is 21633287890801. The next prime is 21633287890853. The reversal of 21633287890825 is 52809878233612.

It can be written as a sum of positive squares in 6 ways, for example, as 1979894016 + 21631307996809 = 44496^2 + 4650947^2 .

It is not a de Polignac number, because 21633287890825 - 2³⁵ = 21598928152457 is a prime.

It is a hoax number, since the sum of its digits (64) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 33281981046 + ... + 33281981695.

Almost surely, 2^{21633287890825} is an apocalyptic number.

21633287890825 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21633287890825 is a deficient number, since it is larger than the sum of its proper divisors (7255471939203).

21633287890825 is a wasteful number, since it uses less digits than its factorization.

21633287890825 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66563962764 (or 66563962759 counting only the distinct ones).

The product of its (nonzero) digits is 69672960, while the sum is 64.

The spelling of 21633287890825 in words is "twenty-one trillion, six hundred thirty-three billion, two hundred eighty-seven million, eight hundred ninety thousand, eight hundred twenty-five".