21206672704 has 112 divisors (see below), whose sum is σ = 51915974400. Its totient is φ = 8393527296.

The previous prime is 21206672689. The next prime is 21206672713. The reversal of 21206672704 is 40727660212.

It is a tau number, because it is divible by the number of its divisors (112).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 263332 + ... + 334300.

Almost surely, 2^21206672704 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21206672704, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25957987200).

21206672704 is an abundant number, since it is smaller than the sum of its proper divisors (30709301696).

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

21206672704 is a wasteful number, since it uses less digits than its factorization.

21206672704 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71040 (or 71030 counting only the distinct ones).

The product of its (nonzero) digits is 56448, while the sum is 37.

The spelling of 21206672704 in words is "twenty-one billion, two hundred six million, six hundred seventy-two thousand, seven hundred four".