31131022321 has 32 divisors (see below), whose sum is σ = 37783500800. Its totient is φ = 25055671680.

The previous prime is 31131022259. The next prime is 31131022327. The reversal of 31131022321 is 12322013113.

It is a cyclic number.

It is not a de Polignac number, because 31131022321 - 2¹⁵ = 31130989553 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (19).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31131022327) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 8864956 + ... + 8868466.

It is an arithmetic number, because the mean of its divisors is an integer number (1180734400).

Almost surely, 2^31131022321 is an apocalyptic number.

It is an amenable number.

31131022321 is a deficient number, since it is larger than the sum of its proper divisors (6652478479).

31131022321 is a wasteful number, since it uses less digits than its factorization.

31131022321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4109.

The product of its (nonzero) digits is 216, while the sum is 19.

Adding to 31131022321 its reverse (12322013113), we get a palindrome (43453035434).

The spelling of 31131022321 in words is "thirty-one billion, one hundred thirty-one million, twenty-two thousand, three hundred twenty-one".