31213120361 has 2 divisors, whose sum is σ = 31213120362. Its totient is φ = 31213120360.

The previous prime is 31213120303. The next prime is 31213120369. The reversal of 31213120361 is 16302131213.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 29775573136 + 1437547225 = 172556^2 + 37915^2 .

It is an emirp because it is prime and its reverse (16302131213) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31213120361 - 2¹⁸ = 31212858217 is a prime.

It is not a weakly prime, because it can be changed into another prime (31213120369) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15606560180 + 15606560181.

It is an arithmetic number, because the mean of its divisors is an integer number (15606560181).

Almost surely, 2^31213120361 is an apocalyptic number.

It is an amenable number.

31213120361 is a deficient number, since it is larger than the sum of its proper divisors (1).

31213120361 is an equidigital number, since it uses as much as digits as its factorization.

31213120361 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 648, while the sum is 23.

Adding to 31213120361 its reverse (16302131213), we get a palindrome (47515251574).

The spelling of 31213120361 in words is "thirty-one billion, two hundred thirteen million, one hundred twenty thousand, three hundred sixty-one".