31231311321 has 16 divisors (see below), whose sum is σ = 47600640000. Its totient is φ = 17842687248.

The previous prime is 31231311283. The next prime is 31231311403. The reversal of 31231311321 is 12311313213.

It is a happy number.

It is not a de Polignac number, because 31231311321 - 2¹¹ = 31231309273 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is not an unprimeable number, because it can be changed into a prime (31231311121) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 54171 + ... + 255728.

It is an arithmetic number, because the mean of its divisors is an integer number (2975040000).

Almost surely, 2^31231311321 is an apocalyptic number.

It is an amenable number.

31231311321 is a deficient number, since it is larger than the sum of its proper divisors (16369328679).

31231311321 is a wasteful number, since it uses less digits than its factorization.

31231311321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 314708.

The product of its digits is 324, while the sum is 21.

Adding to 31231311321 its reverse (12311313213), we get a palindrome (43542624534).

The spelling of 31231311321 in words is "thirty-one billion, two hundred thirty-one million, three hundred eleven thousand, three hundred twenty-one".