21389910372 has 72 divisors (see below), whose sum is σ = 55558828416. Its totient is φ = 6935367744.

The previous prime is 21389910359. The next prime is 21389910389. The reversal of 21389910372 is 27301998312.

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, 237018 + ... + 314574.

Almost surely, 2^21389910372 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 21389910372, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27779414208).

21389910372 is an abundant number, since it is smaller than the sum of its proper divisors (34168918044).

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

21389910372 is a wasteful number, since it uses less digits than its factorization.

21389910372 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77777 (or 77772 counting only the distinct ones).

The product of its (nonzero) digits is 163296, while the sum is 45.

The spelling of 21389910372 in words is "twenty-one billion, three hundred eighty-nine million, nine hundred ten thousand, three hundred seventy-two".