21439489536 has 120 divisors (see below), whose sum is σ = 64167887784. Its totient is φ = 7146455040.

The previous prime is 21439489529. The next prime is 21439489579. The reversal of 21439489536 is 63598493412.

21439489536 is a `hidden beast` number, since 2 + 14 + 3 + 94 + 8 + 9 + 536 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 38256 + ... + 210576.

Almost surely, 2^21439489536 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 21439489536, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32083943892).

21439489536 is an abundant number, since it is smaller than the sum of its proper divisors (42728398248).

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

21439489536 is an frugal number, since it uses more digits than its factorization.

21439489536 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 172354 (or 172326 counting only the distinct ones).

The product of its digits is 5598720, while the sum is 54.

The spelling of 21439489536 in words is "twenty-one billion, four hundred thirty-nine million, four hundred eighty-nine thousand, five hundred thirty-six".