57072309 has 24 divisors (see below), whose sum is σ = 90588960. Its totient is φ = 31850784.

The previous prime is 57072307. The next prime is 57072313. The reversal of 57072309 is 90327075.

It is not a de Polignac number, because 57072309 - 2¹ = 57072307 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 57072309.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (57072307) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1807 + ... + 10835.

It is an arithmetic number, because the mean of its divisors is an integer number (3774540).

Almost surely, 2^57072309 is an apocalyptic number.

It is an amenable number.

57072309 is a deficient number, since it is larger than the sum of its proper divisors (33516651).

57072309 is a wasteful number, since it uses less digits than its factorization.

57072309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9089 (or 9082 counting only the distinct ones).

The product of its (nonzero) digits is 13230, while the sum is 33.

The square root of 57072309 is about 7554.6216980071. The cubic root of 57072309 is about 385.0127819448.

The spelling of 57072309 in words is "fifty-seven million, seventy-two thousand, three hundred nine".