21231644337 has 24 divisors (see below), whose sum is σ = 30765945600. Its totient is φ = 14109258240.

The previous prime is 21231644327. The next prime is 21231644341. The reversal of 21231644337 is 73344613212.

21231644337 is a `hidden beast` number, since 2 + 1 + 2 + 3 + 1 + 644 + 3 + 3 + 7 = 666.

It is not a de Polignac number, because 21231644337 - 2¹⁰ = 21231643313 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21231644327) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5845512 + ... + 5849142.

It is an arithmetic number, because the mean of its divisors is an integer number (1281914400).

Almost surely, 2^21231644337 is an apocalyptic number.

It is an amenable number.

21231644337 is a deficient number, since it is larger than the sum of its proper divisors (9534301263).

21231644337 is a wasteful number, since it uses less digits than its factorization.

21231644337 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5533 (or 5530 counting only the distinct ones).

The product of its digits is 72576, while the sum is 36.

The spelling of 21231644337 in words is "twenty-one billion, two hundred thirty-one million, six hundred forty-four thousand, three hundred thirty-seven".