31261402121 has 2 divisors, whose sum is σ = 31261402122. Its totient is φ = 31261402120.

The previous prime is 31261402087. The next prime is 31261402147. The reversal of 31261402121 is 12120416213.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 30724831225 + 536570896 = 175285^2 + 23164^2 .

It is a cyclic number.

It is not a de Polignac number, because 31261402121 - 2¹⁴ = 31261385737 is a prime.

It is not a weakly prime, because it can be changed into another prime (31261402321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15630701060 + 15630701061.

It is an arithmetic number, because the mean of its divisors is an integer number (15630701061).

Almost surely, 2^31261402121 is an apocalyptic number.

It is an amenable number.

31261402121 is a deficient number, since it is larger than the sum of its proper divisors (1).

31261402121 is an equidigital number, since it uses as much as digits as its factorization.

31261402121 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 576, while the sum is 23.

Adding to 31261402121 its reverse (12120416213), we get a palindrome (43381818334).

The spelling of 31261402121 in words is "thirty-one billion, two hundred sixty-one million, four hundred two thousand, one hundred twenty-one".