57172561891 has 2 divisors, whose sum is σ = 57172561892. Its totient is φ = 57172561890.

The previous prime is 57172561847. The next prime is 57172561969. The reversal of 57172561891 is 19816527175.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 57172561891 - 2²⁷ = 57038344163 is a prime.

It is not a weakly prime, because it can be changed into another prime (57172561291) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 28586280945 + 28586280946.

It is an arithmetic number, because the mean of its divisors is an integer number (28586280946).

Almost surely, 2^57172561891 is an apocalyptic number.

57172561891 is a deficient number, since it is larger than the sum of its proper divisors (1).

57172561891 is an equidigital number, since it uses as much as digits as its factorization.

57172561891 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1058400, while the sum is 52.

It can be divided in two parts, 571725 and 61891, that added together give a square (633616 = 796²).

The spelling of 57172561891 in words is "fifty-seven billion, one hundred seventy-two million, five hundred sixty-one thousand, eight hundred ninety-one".