31212322081 has 2 divisors, whose sum is σ = 31212322082. Its totient is φ = 31212322080.

The previous prime is 31212322049. The next prime is 31212322093. The reversal of 31212322081 is 18022321213.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21260264481 + 9952057600 = 145809^2 + 99760^2 .

It is a cyclic number.

It is not a de Polignac number, because 31212322081 - 2⁵ = 31212322049 is a prime.

It is a super-2 number, since 2×31212322081² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (31212323081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15606161040 + 15606161041.

It is an arithmetic number, because the mean of its divisors is an integer number (15606161041).

Almost surely, 2^31212322081 is an apocalyptic number.

It is an amenable number.

31212322081 is a deficient number, since it is larger than the sum of its proper divisors (1).

31212322081 is an equidigital number, since it uses as much as digits as its factorization.

31212322081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1152, while the sum is 25.

Adding to 31212322081 its reverse (18022321213), we get a palindrome (49234643294).

The spelling of 31212322081 in words is "thirty-one billion, two hundred twelve million, three hundred twenty-two thousand, eighty-one".