31115508491 has 2 divisors, whose sum is σ = 31115508492. Its totient is φ = 31115508490.

The previous prime is 31115508469. The next prime is 31115508509. The reversal of 31115508491 is 19480551113.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 31115508491 - 2¹⁸ = 31115246347 is a prime.

It is not a weakly prime, because it can be changed into another prime (31115508421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15557754245 + 15557754246.

It is an arithmetic number, because the mean of its divisors is an integer number (15557754246).

Almost surely, 2^31115508491 is an apocalyptic number.

31115508491 is a deficient number, since it is larger than the sum of its proper divisors (1).

31115508491 is an equidigital number, since it uses as much as digits as its factorization.

31115508491 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 21600, while the sum is 38.

The spelling of 31115508491 in words is "thirty-one billion, one hundred fifteen million, five hundred eight thousand, four hundred ninety-one".