31991685728701 has 2 divisors, whose sum is σ = 31991685728702. Its totient is φ = 31991685728700.

The previous prime is 31991685728689. The next prime is 31991685728711. The reversal of 31991685728701 is 10782758619913.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 29475115951801 + 2516569776900 = 5429099^2 + 1586370^2 .

It is a cyclic number.

It is not a de Polignac number, because 31991685728701 - 2²¹ = 31991683631549 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31991685728711) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15995842864350 + 15995842864351.

It is an arithmetic number, because the mean of its divisors is an integer number (15995842864351).

Almost surely, 2^{31991685728701} is an apocalyptic number.

It is an amenable number.

31991685728701 is a deficient number, since it is larger than the sum of its proper divisors (1).

31991685728701 is an equidigital number, since it uses as much as digits as its factorization.

31991685728701 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 45722880, while the sum is 67.

The spelling of 31991685728701 in words is "thirty-one trillion, nine hundred ninety-one billion, six hundred eighty-five million, seven hundred twenty-eight thousand, seven hundred one".