21904625412 has 18 divisors (see below), whose sum is σ = 55370025438. Its totient is φ = 7301541792.

The previous prime is 21904625371. The next prime is 21904625447. The reversal of 21904625412 is 21452640912.

It is a happy number.

21904625412 is a `hidden beast` number, since 2 + 19 + 0 + 4 + 625 + 4 + 12 = 666.

It can be written as a sum of positive squares in only one way, i.e., 21672550656 + 232074756 = 147216^2 + 15234^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a super-2 number, since 2×21904625412² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 608461817 = 21904625412 / (2 + 1 + 9 + 0 + 4 + 6 + 2 + 5 + 4 + 1 + 2).

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 304230873 + ... + 304230944.

Almost surely, 2^21904625412 is an apocalyptic number.

It is an amenable number.

21904625412 is an abundant number, since it is smaller than the sum of its proper divisors (33465400026).

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

21904625412 is a wasteful number, since it uses less digits than its factorization.

21904625412 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 608461827 (or 608461822 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 36.

The spelling of 21904625412 in words is "twenty-one billion, nine hundred four million, six hundred twenty-five thousand, four hundred twelve".