21320120331 has 12 divisors (see below), whose sum is σ = 30812301520. Its totient is φ = 14205764880.

The previous prime is 21320120329. The next prime is 21320120377. The reversal of 21320120331 is 13302102312.

21320120331 is a `hidden beast` number, since 2 + 1 + 320 + 12 + 0 + 331 = 666.

It is not a de Polignac number, because 21320120331 - 2¹ = 21320120329 is a prime.

It is a super-2 number, since 2×21320120331² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21320120231) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 619711 + ... + 653208.

Almost surely, 2^21320120331 is an apocalyptic number.

21320120331 is a deficient number, since it is larger than the sum of its proper divisors (9492181189).

21320120331 is a wasteful number, since it uses less digits than its factorization.

21320120331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1274786 (or 1274783 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

Adding to 21320120331 its reverse (13302102312), we get a palindrome (34622222643).

The spelling of 21320120331 in words is "twenty-one billion, three hundred twenty million, one hundred twenty thousand, three hundred thirty-one".