21213645032 has 16 divisors (see below), whose sum is σ = 39844528260. Its totient is φ = 10588437504.

The previous prime is 21213645023. The next prime is 21213645059. The reversal of 21213645032 is 23054631212.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 15536625316 + 5677019716 = 124646^2 + 75346^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21213644986 and 21213645004.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2293223 + ... + 2302454.

Almost surely, 2^21213645032 is an apocalyptic number.

It is an amenable number.

21213645032 is a deficient number, since it is larger than the sum of its proper divisors (18630883228).

21213645032 is a wasteful number, since it uses less digits than its factorization.

21213645032 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4596260 (or 4596256 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 29.

The spelling of 21213645032 in words is "twenty-one billion, two hundred thirteen million, six hundred forty-five thousand, thirty-two".