320645857 has 24 divisors (see below), whose sum is σ = 400423176. Its totient is φ = 255080448.

The previous prime is 320645833. The next prime is 320645861. The reversal of 320645857 is 758546023.

It can be written as a sum of positive squares in 4 ways, for example, as 93721761 + 226924096 = 9681^2 + 15064^2 .

It is not a de Polignac number, because 320645857 - 2¹⁵ = 320613089 is a prime.

It is a super-2 number, since 2×320645857² = 205627531222528898, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (320645807) 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, 58173 + ... + 63445.

It is an arithmetic number, because the mean of its divisors is an integer number (16684299).

Almost surely, 2^320645857 is an apocalyptic number.

It is an amenable number.

320645857 is a deficient number, since it is larger than the sum of its proper divisors (79777319).

320645857 is a wasteful number, since it uses less digits than its factorization.

320645857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5377 (or 5370 counting only the distinct ones).

The product of its (nonzero) digits is 201600, while the sum is 40.

The square root of 320645857 is about 17906.5869723965. The cubic root of 320645857 is about 684.4502360717.

The spelling of 320645857 in words is "three hundred twenty million, six hundred forty-five thousand, eight hundred fifty-seven".