21045647392 has 144 divisors (see below), whose sum is σ = 53473724640. Its totient is φ = 8060236800.

The previous prime is 21045647387. The next prime is 21045647417. The reversal of 21045647392 is 29374654012.

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, 1007292 + ... + 1027972.

It is an arithmetic number, because the mean of its divisors is an integer number (371345310).

Almost surely, 2^21045647392 is an apocalyptic number.

21045647392 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21045647392, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26736862320).

21045647392 is an abundant number, since it is smaller than the sum of its proper divisors (32428077248).

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

21045647392 is a wasteful number, since it uses less digits than its factorization.

21045647392 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20775 (or 20760 counting only the distinct ones).

The product of its (nonzero) digits is 362880, while the sum is 43.

The spelling of 21045647392 in words is "twenty-one billion, forty-five million, six hundred forty-seven thousand, three hundred ninety-two".