57491809 has 4 divisors (see below), whose sum is σ = 57515200. Its totient is φ = 57468420.

The previous prime is 57491767. The next prime is 57491827. The reversal of 57491809 is 90819475.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 57491809 - 2¹³ = 57483617 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (57491899) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7509 + ... + 13090.

It is an arithmetic number, because the mean of its divisors is an integer number (14378800).

Almost surely, 2^57491809 is an apocalyptic number.

It is an amenable number.

57491809 is a deficient number, since it is larger than the sum of its proper divisors (23391).

57491809 is a wasteful number, since it uses less digits than its factorization.

57491809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23390.

The product of its (nonzero) digits is 90720, while the sum is 43.

The square root of 57491809 is about 7582.3353262699. The cubic root of 57491809 is about 385.9538030747.

The spelling of 57491809 in words is "fifty-seven million, four hundred ninety-one thousand, eight hundred nine".