31947253991 has 2 divisors, whose sum is σ = 31947253992. Its totient is φ = 31947253990.

The previous prime is 31947253967. The next prime is 31947253993. The reversal of 31947253991 is 19935274913.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 31947253991 - 2¹⁸ = 31946991847 is a prime.

Together with 31947253993, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31947253993) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15973626995 + 15973626996.

It is an arithmetic number, because the mean of its divisors is an integer number (15973626996).

Almost surely, 2^31947253991 is an apocalyptic number.

31947253991 is a deficient number, since it is larger than the sum of its proper divisors (1).

31947253991 is an equidigital number, since it uses as much as digits as its factorization.

31947253991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1837080, while the sum is 53.

The spelling of 31947253991 in words is "thirty-one billion, nine hundred forty-seven million, two hundred fifty-three thousand, nine hundred ninety-one".