21304623500 has 24 divisors (see below), whose sum is σ = 46529298816. Its totient is φ = 8521849200.

The previous prime is 21304623493. The next prime is 21304623521. The reversal of 21304623500 is 532640312.

It is a self number, because there is not a number n which added to its sum of digits gives 21304623500.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21304124 + ... + 21305123.

It is an arithmetic number, because the mean of its divisors is an integer number (1938720784).

Almost surely, 2^21304623500 is an apocalyptic number.

21304623500 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21304623500 is an abundant number, since it is smaller than the sum of its proper divisors (25224675316).

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

21304623500 is a wasteful number, since it uses less digits than its factorization.

21304623500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42609266 (or 42609254 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 26.

The spelling of 21304623500 in words is "twenty-one billion, three hundred four million, six hundred twenty-three thousand, five hundred".