31587145991 has 2 divisors, whose sum is σ = 31587145992. Its totient is φ = 31587145990.

The previous prime is 31587145981. The next prime is 31587146053. The reversal of 31587145991 is 19954178513.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31587145991 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31587145951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15793572995 + 15793572996.

It is an arithmetic number, because the mean of its divisors is an integer number (15793572996).

Almost surely, 2^31587145991 is an apocalyptic number.

31587145991 is a deficient number, since it is larger than the sum of its proper divisors (1).

31587145991 is an equidigital number, since it uses as much as digits as its factorization.

31587145991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1360800, while the sum is 53.

The spelling of 31587145991 in words is "thirty-one billion, five hundred eighty-seven million, one hundred forty-five thousand, nine hundred ninety-one".