21633125166 has 32 divisors (see below), whose sum is σ = 48419481600. Its totient is φ = 7159161240.

The previous prime is 21633125153. The next prime is 21633125167. The reversal of 21633125166 is 66152133612.

21633125166 is a `hidden beast` number, since 2 + 1 + 633 + 1 + 2 + 5 + 16 + 6 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 21633125166.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21633125167) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1433550 + ... + 1448561.

It is an arithmetic number, because the mean of its divisors is an integer number (1513108800).

Almost surely, 2^21633125166 is an apocalyptic number.

21633125166 is an abundant number, since it is smaller than the sum of its proper divisors (26786356434).

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

21633125166 is a wasteful number, since it uses less digits than its factorization.

21633125166 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2882261 (or 2882255 counting only the distinct ones).

The product of its digits is 38880, while the sum is 36.

Adding to 21633125166 its reverse (66152133612), we get a palindrome (87785258778).

The spelling of 21633125166 in words is "twenty-one billion, six hundred thirty-three million, one hundred twenty-five thousand, one hundred sixty-six".