645855457 has 16 divisors (see below), whose sum is σ = 719373312. Its totient is φ = 575818560.

The previous prime is 645855443. The next prime is 645855473. The reversal of 645855457 is 754558546.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-645855457 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 645855457.

It is not an unprimeable number, because it can be changed into a prime (645855437) 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, 259503 + ... + 261979.

It is an arithmetic number, because the mean of its divisors is an integer number (44960832).

Almost surely, 2^645855457 is an apocalyptic number.

It is an amenable number.

645855457 is a deficient number, since it is larger than the sum of its proper divisors (73517855).

645855457 is a wasteful number, since it uses less digits than its factorization.

645855457 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3168.

The product of its digits is 3360000, while the sum is 49.

The square root of 645855457 is about 25413.6864110660. The cubic root of 645855457 is about 864.3940679425.

The spelling of 645855457 in words is "six hundred forty-five million, eight hundred fifty-five thousand, four hundred fifty-seven".