505367778931 has 2 divisors, whose sum is σ = 505367778932. Its totient is φ = 505367778930.

The previous prime is 505367778913. The next prime is 505367778961. The reversal of 505367778931 is 139877763505.

It is a happy number.

Together with previous prime (505367778913) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 505367778931 - 2³¹ = 503220295283 is a prime.

It is a super-2 number, since 2×505367778931² (a number of 24 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 505367778931.

It is not a weakly prime, because it can be changed into another prime (505367778961) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 252683889465 + 252683889466.

It is an arithmetic number, because the mean of its divisors is an integer number (252683889466).

Almost surely, 2^505367778931 is an apocalyptic number.

505367778931 is a deficient number, since it is larger than the sum of its proper divisors (1).

505367778931 is an equidigital number, since it uses as much as digits as its factorization.

505367778931 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 33339600, while the sum is 61.

The spelling of 505367778931 in words is "five hundred five billion, three hundred sixty-seven million, seven hundred seventy-eight thousand, nine hundred thirty-one".