645569057 has 8 divisors (see below), whose sum is σ = 739440000. Its totient is φ = 552109824.

The previous prime is 645569021. The next prime is 645569063. The reversal of 645569057 is 750965546.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 645569057 - 2⁶ = 645568993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (645569077) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 99557 + ... + 105842.

It is an arithmetic number, because the mean of its divisors is an integer number (92430000).

Almost surely, 2^645569057 is an apocalyptic number.

It is an amenable number.

645569057 is a deficient number, since it is larger than the sum of its proper divisors (93870943).

645569057 is a wasteful number, since it uses less digits than its factorization.

645569057 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 205855.

The product of its (nonzero) digits is 1134000, while the sum is 47.

The square root of 645569057 is about 25408.0510271843. The cubic root of 645569057 is about 864.2662792550.

The spelling of 645569057 in words is "six hundred forty-five million, five hundred sixty-nine thousand, fifty-seven".