21012521230 has 48 divisors (see below), whose sum is σ = 39951416160. Its totient is φ = 7955970624.

The previous prime is 21012521227. The next prime is 21012521251. The reversal of 21012521230 is 3212521012.

It is a Harshad number since it is a multiple of its sum of digits (19).

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

It is a junction number, because it is equal to n+sod(n) for n = 21012521198 and 21012521207.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7532676 + ... + 7535464.

It is an arithmetic number, because the mean of its divisors is an integer number (832321170).

Almost surely, 2^21012521230 is an apocalyptic number.

21012521230 is a deficient number, since it is larger than the sum of its proper divisors (18938894930).

21012521230 is a wasteful number, since it uses less digits than its factorization.

21012521230 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4921 (or 4902 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 19.

The spelling of 21012521230 in words is "twenty-one billion, twelve million, five hundred twenty-one thousand, two hundred thirty".