505957891 has 2 divisors, whose sum is σ = 505957892. Its totient is φ = 505957890.

The previous prime is 505957883. The next prime is 505957931. The reversal of 505957891 is 198759505.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 505957891 - 2³ = 505957883 is a prime.

It is not a weakly prime, because it can be changed into another prime (505957811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 252978945 + 252978946.

It is an arithmetic number, because the mean of its divisors is an integer number (252978946).

Almost surely, 2^505957891 is an apocalyptic number.

505957891 is a deficient number, since it is larger than the sum of its proper divisors (1).

505957891 is an equidigital number, since it uses as much as digits as its factorization.

505957891 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 567000, while the sum is 49.

The square root of 505957891 is about 22493.5077522382. The cubic root of 505957891 is about 796.8406074527.

The spelling of 505957891 in words is "five hundred five million, nine hundred fifty-seven thousand, eight hundred ninety-one".