642840667 has 16 divisors (see below), whose sum is σ = 755758080. Its totient is φ = 535364928.

The previous prime is 642840647. The next prime is 642840691. The reversal of 642840667 is 766048246.

642840667 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 642840667 - 2¹⁵ = 642807899 is a prime.

It is not an unprimeable number, because it can be changed into a prime (642840607) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 38703 + ... + 52759.

It is an arithmetic number, because the mean of its divisors is an integer number (47234880).

Almost surely, 2^642840667 is an apocalyptic number.

642840667 is a deficient number, since it is larger than the sum of its proper divisors (112917413).

642840667 is a wasteful number, since it uses less digits than its factorization.

642840667 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14250.

The product of its (nonzero) digits is 387072, while the sum is 43.

The square root of 642840667 is about 25354.3027314892. The cubic root of 642840667 is about 863.0470008287.

The spelling of 642840667 in words is "six hundred forty-two million, eight hundred forty thousand, six hundred sixty-seven".