642046257 has 10 divisors (see below), whose sum is σ = 959106258. Its totient is φ = 428030784.

The previous prime is 642046247. The next prime is 642046261. The reversal of 642046257 is 752640246.

642046257 is a `hidden beast` number, since 6 + 4 + 20 + 4 + 625 + 7 = 666.

It can be written as a sum of positive squares in only one way, i.e., 379314576 + 262731681 = 19476^2 + 16209^2 .

It is not a de Polignac number, because 642046257 - 2⁷ = 642046129 is a prime.

It is a super-2 number, since 2×642046257² = 824446792255420098, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (642046247) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 3963168 + ... + 3963329.

Almost surely, 2^642046257 is an apocalyptic number.

It is an amenable number.

642046257 is a deficient number, since it is larger than the sum of its proper divisors (317060001).

642046257 is an equidigital number, since it uses as much as digits as its factorization.

642046257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7926509 (or 7926500 counting only the distinct ones).

The product of its (nonzero) digits is 80640, while the sum is 36.

The square root of 642046257 is about 25338.6317112823. The cubic root of 642046257 is about 862.6913420475.

The spelling of 642046257 in words is "six hundred forty-two million, forty-six thousand, two hundred fifty-seven".