31491921311 has 2 divisors, whose sum is σ = 31491921312. Its totient is φ = 31491921310.

The previous prime is 31491921289. The next prime is 31491921353. The reversal of 31491921311 is 11312919413.

It is a weak prime.

It is an emirp because it is prime and its reverse (11312919413) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31491921311 - 2³⁴ = 14312052127 is a prime.

It is a super-2 number, since 2×31491921311² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31491921511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15745960655 + 15745960656.

It is an arithmetic number, because the mean of its divisors is an integer number (15745960656).

Almost surely, 2^31491921311 is an apocalyptic number.

31491921311 is a deficient number, since it is larger than the sum of its proper divisors (1).

31491921311 is an equidigital number, since it uses as much as digits as its factorization.

31491921311 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5832, while the sum is 35.

The spelling of 31491921311 in words is "thirty-one billion, four hundred ninety-one million, nine hundred twenty-one thousand, three hundred eleven".