31263511261 has 2 divisors, whose sum is σ = 31263511262. Its totient is φ = 31263511260.

The previous prime is 31263511217. The next prime is 31263511267. The reversal of 31263511261 is 16211536213.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 30719222361 + 544288900 = 175269^2 + 23330^2 .

It is an emirp because it is prime and its reverse (16211536213) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31263511261 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31263511267) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15631755630 + 15631755631.

It is an arithmetic number, because the mean of its divisors is an integer number (15631755631).

Almost surely, 2^31263511261 is an apocalyptic number.

It is an amenable number.

31263511261 is a deficient number, since it is larger than the sum of its proper divisors (1).

31263511261 is an equidigital number, since it uses as much as digits as its factorization.

31263511261 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6480, while the sum is 31.

The spelling of 31263511261 in words is "thirty-one billion, two hundred sixty-three million, five hundred eleven thousand, two hundred sixty-one".