31213021331 has 8 divisors (see below), whose sum is σ = 31947904560. Its totient is φ = 30478547232.

The previous prime is 31213021313. The next prime is 31213021361. The reversal of 31213021331 is 13312031213.

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

It is not a de Polignac number, because 31213021331 - 2¹⁴ = 31213004947 is a prime.

It is a super-2 number, since 2×31213021331² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31213021361) 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, 54905 + ... + 255813.

It is an arithmetic number, because the mean of its divisors is an integer number (3993488070).

Almost surely, 2^31213021331 is an apocalyptic number.

31213021331 is a deficient number, since it is larger than the sum of its proper divisors (734883229).

31213021331 is a wasteful number, since it uses less digits than its factorization.

31213021331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 204565.

The product of its (nonzero) digits is 324, while the sum is 20.

Adding to 31213021331 its reverse (13312031213), we get a palindrome (44525052544).

The spelling of 31213021331 in words is "thirty-one billion, two hundred thirteen million, twenty-one thousand, three hundred thirty-one".