31064907781 has 2 divisors, whose sum is σ = 31064907782. Its totient is φ = 31064907780.

The previous prime is 31064907697. The next prime is 31064907791. The reversal of 31064907781 is 18770946013.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21494198881 + 9570708900 = 146609^2 + 97830^2 .

It is a cyclic number.

It is not a de Polignac number, because 31064907781 - 2¹¹ = 31064905733 is a prime.

It is a super-2 number, since 2×31064907781² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31064907791) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15532453890 + 15532453891.

It is an arithmetic number, because the mean of its divisors is an integer number (15532453891).

Almost surely, 2^31064907781 is an apocalyptic number.

It is an amenable number.

31064907781 is a deficient number, since it is larger than the sum of its proper divisors (1).

31064907781 is an equidigital number, since it uses as much as digits as its factorization.

31064907781 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 254016, while the sum is 46.

The spelling of 31064907781 in words is "thirty-one billion, sixty-four million, nine hundred seven thousand, seven hundred eighty-one".