21312332291 has 8 divisors (see below), whose sum is σ = 21607120224. Its totient is φ = 21019187200.

The previous prime is 21312332233. The next prime is 21312332309. The reversal of 21312332291 is 19223321312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21312332291 - 2¹⁴ = 21312315907 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21312332201) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 384575 + ... + 436488.

It is an arithmetic number, because the mean of its divisors is an integer number (2700890028).

Almost surely, 2^21312332291 is an apocalyptic number.

21312332291 is a deficient number, since it is larger than the sum of its proper divisors (294787933).

21312332291 is a wasteful number, since it uses less digits than its factorization.

21312332291 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 821421.

The product of its digits is 3888, while the sum is 29.

The spelling of 21312332291 in words is "twenty-one billion, three hundred twelve million, three hundred thirty-two thousand, two hundred ninety-one".