57261991 has 16 divisors (see below), whose sum is σ = 62668800. Its totient is φ = 52120800.

The previous prime is 57261989. The next prime is 57262033. The reversal of 57261991 is 19916275.

It is not a de Polignac number, because 57261991 - 2¹ = 57261989 is a prime.

It is a super-2 number, since 2×57261991² = 6557871226568162, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (57261901) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 112245 + ... + 112753.

It is an arithmetic number, because the mean of its divisors is an integer number (3916800).

It is a vampire number, since it can be written as 5921 ⋅ 9671 (with its own digits).

Almost surely, 2^57261991 is an apocalyptic number.

57261991 is a deficient number, since it is larger than the sum of its proper divisors (5406809).

57261991 is a wasteful number, since it uses less digits than its factorization.

57261991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 750.

The product of its digits is 34020, while the sum is 40.

The square root of 57261991 is about 7567.1653213076. The cubic root of 57261991 is about 385.4388451784.

The spelling of 57261991 in words is "fifty-seven million, two hundred sixty-one thousand, nine hundred ninety-one".