31991985241 has 4 divisors (see below), whose sum is σ = 31995005184. Its totient is φ = 31988965300.

The previous prime is 31991985209. The next prime is 31991985269. The reversal of 31991985241 is 14258919913.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 14258919913 = 7 ⋅2036988559.

It is a cyclic number.

It is not a de Polignac number, because 31991985241 - 2⁵ = 31991985209 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31991985341) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1494025 + ... + 1515286.

It is an arithmetic number, because the mean of its divisors is an integer number (7998751296).

Almost surely, 2^31991985241 is an apocalyptic number.

It is an amenable number.

31991985241 is a deficient number, since it is larger than the sum of its proper divisors (3019943).

31991985241 is a wasteful number, since it uses less digits than its factorization.

31991985241 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3019942.

The product of its digits is 699840, while the sum is 52.

The spelling of 31991985241 in words is "thirty-one billion, nine hundred ninety-one million, nine hundred eighty-five thousand, two hundred forty-one".