642118907 has 2 divisors, whose sum is σ = 642118908. Its totient is φ = 642118906.

The previous prime is 642118843. The next prime is 642118921. The reversal of 642118907 is 709811246.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 642118907 - 2⁶ = 642118843 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (642118937) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321059453 + 321059454.

It is an arithmetic number, because the mean of its divisors is an integer number (321059454).

Almost surely, 2^642118907 is an apocalyptic number.

642118907 is a deficient number, since it is larger than the sum of its proper divisors (1).

642118907 is an equidigital number, since it uses as much as digits as its factorization.

642118907 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 24192, while the sum is 38.

The square root of 642118907 is about 25340.0652524811. The cubic root of 642118907 is about 862.7238797665.

The spelling of 642118907 in words is "six hundred forty-two million, one hundred eighteen thousand, nine hundred seven".