642791907 has 54 divisors (see below), whose sum is σ = 1012611132. Its totient is φ = 392826672.

The previous prime is 642791899. The next prime is 642791911. The reversal of 642791907 is 709197246.

It is not a de Polignac number, because 642791907 - 2³ = 642791899 is a prime.

It is not an unprimeable number, because it can be changed into a prime (642791917) by changing a digit.

It is a polite number, since it can be written in 53 ways as a sum of consecutive naturals, for example, 6007348 + ... + 6007454.

It is an arithmetic number, because the mean of its divisors is an integer number (18752058).

Almost surely, 2^642791907 is an apocalyptic number.

642791907 is a deficient number, since it is larger than the sum of its proper divisors (369819225).

642791907 is a wasteful number, since it uses less digits than its factorization.

642791907 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 237 (or 172 counting only the distinct ones).

The product of its (nonzero) digits is 190512, while the sum is 45.

The square root of 642791907 is about 25353.3411407649. The cubic root of 642791907 is about 863.0251793324.

The spelling of 642791907 in words is "six hundred forty-two million, seven hundred ninety-one thousand, nine hundred seven".