168513931 has 2 divisors, whose sum is σ = 168513932. Its totient is φ = 168513930.

The previous prime is 168513913. The next prime is 168513949. The reversal of 168513931 is 139315861.

Together with previous prime (168513913) it forms an Ormiston pair, because they use the same digits, order apart.

It is a balanced prime because it is at equal distance from previous prime (168513913) and next prime (168513949).

It is an emirp because it is prime and its reverse (139315861) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 168513931 - 2⁵ = 168513899 is a prime.

It is a super-2 number, since 2×168513931² = 56793889882145522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (168513901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 84256965 + 84256966.

It is an arithmetic number, because the mean of its divisors is an integer number (84256966).

Almost surely, 2^168513931 is an apocalyptic number.

168513931 is a deficient number, since it is larger than the sum of its proper divisors (1).

168513931 is an equidigital number, since it uses as much as digits as its factorization.

168513931 is an evil number, because the sum of its binary digits is even.

The product of its digits is 19440, while the sum is 37.

The square root of 168513931 is about 12981.2915767269. The cubic root of 168513931 is about 552.3469199102.

The spelling of 168513931 in words is "one hundred sixty-eight million, five hundred thirteen thousand, nine hundred thirty-one".