855513097931 has 2 divisors, whose sum is σ = 855513097932. Its totient is φ = 855513097930.

The previous prime is 855513097913. The next prime is 855513097939. The reversal of 855513097931 is 139790315558.

Together with previous prime (855513097913) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 855513097931 - 2⁶ = 855513097867 is a prime.

It is a super-2 number, since 2×855513097931² (a number of 25 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (855513097939) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 427756548965 + 427756548966.

It is an arithmetic number, because the mean of its divisors is an integer number (427756548966).

Almost surely, 2^855513097931 is an apocalyptic number.

855513097931 is a deficient number, since it is larger than the sum of its proper divisors (1).

855513097931 is an equidigital number, since it uses as much as digits as its factorization.

855513097931 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5103000, while the sum is 56.

The spelling of 855513097931 in words is "eight hundred fifty-five billion, five hundred thirteen million, ninety-seven thousand, nine hundred thirty-one".