21006353604 has 24 divisors (see below), whose sum is σ = 49017251808. Its totient is φ = 7001771200.

The previous prime is 21006353591. The next prime is 21006353617. The reversal of 21006353604 is 40635360012.

It is an interprime number because it is at equal distance from previous prime (21006353591) and next prime (21006353617).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 357304 + ... + 411920.

It is an arithmetic number, because the mean of its divisors is an integer number (2042385492).

Almost surely, 2^21006353604 is an apocalyptic number.

It is an amenable number.

21006353604 is an abundant number, since it is smaller than the sum of its proper divisors (28010898204).

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

21006353604 is a wasteful number, since it uses less digits than its factorization.

21006353604 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 86675 (or 86673 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 30.

The spelling of 21006353604 in words is "twenty-one billion, six million, three hundred fifty-three thousand, six hundred four".