57215091 has 4 divisors (see below), whose sum is σ = 76286792. Its totient is φ = 38143392.

The previous prime is 57215089. The next prime is 57215107. The reversal of 57215091 is 19051275.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 57215091 - 2¹ = 57215089 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (57215021) 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, 9535846 + ... + 9535851.

It is an arithmetic number, because the mean of its divisors is an integer number (19071698).

Almost surely, 2^57215091 is an apocalyptic number.

57215091 is a deficient number, since it is larger than the sum of its proper divisors (19071701).

57215091 is a wasteful number, since it uses less digits than its factorization.

57215091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19071700.

The product of its (nonzero) digits is 3150, while the sum is 30.

The square root of 57215091 is about 7564.0657717923. The cubic root of 57215091 is about 385.3335861804. Note that the first 3 decimals are identical.

The spelling of 57215091 in words is "fifty-seven million, two hundred fifteen thousand, ninety-one".