646331057 has 4 divisors (see below), whose sum is σ = 646414836. Its totient is φ = 646247280.

The previous prime is 646331053. The next prime is 646331069. The reversal of 646331057 is 750133646.

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

It can be written as a sum of positive squares in 2 ways, for example, as 428945521 + 217385536 = 20711^2 + 14744^2 .

It is a cyclic number.

It is not a de Polignac number, because 646331057 - 2² = 646331053 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (646331053) 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, 28994 + ... + 46187.

It is an arithmetic number, because the mean of its divisors is an integer number (161603709).

Almost surely, 2^646331057 is an apocalyptic number.

It is an amenable number.

646331057 is a deficient number, since it is larger than the sum of its proper divisors (83779).

646331057 is an equidigital number, since it uses as much as digits as its factorization.

646331057 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83778.

The product of its (nonzero) digits is 45360, while the sum is 35.

The square root of 646331057 is about 25423.0418518320. The cubic root of 646331057 is about 864.6061922624.

The spelling of 646331057 in words is "six hundred forty-six million, three hundred thirty-one thousand, fifty-seven".