31231211120321 has 4 divisors (see below), whose sum is σ = 31231228057812. Its totient is φ = 31231194182832.

The previous prime is 31231211120293. The next prime is 31231211120363. The reversal of 31231211120321 is 12302111213213.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 19753758030400 + 11477453089921 = 4444520^2 + 3387839^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31231211120321 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31231211120381) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5310206 + ... + 9521591.

It is an arithmetic number, because the mean of its divisors is an integer number (7807807014453).

Almost surely, 2^{31231211120321} is an apocalyptic number.

It is an amenable number.

31231211120321 is a deficient number, since it is larger than the sum of its proper divisors (16937491).

31231211120321 is a wasteful number, since it uses less digits than its factorization.

31231211120321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16937490.

The product of its (nonzero) digits is 432, while the sum is 23.

Adding to 31231211120321 its reverse (12302111213213), we get a palindrome (43533322333534).

The spelling of 31231211120321 in words is "thirty-one trillion, two hundred thirty-one billion, two hundred eleven million, one hundred twenty thousand, three hundred twenty-one".