642406207 has 4 divisors (see below), whose sum is σ = 676217080. Its totient is φ = 608595336.

The previous prime is 642406201. The next prime is 642406229. The reversal of 642406207 is 702604246.

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

It is a cyclic number.

It is not a de Polignac number, because 642406207 - 2²⁷ = 508188479 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642406201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16905408 + ... + 16905445.

It is an arithmetic number, because the mean of its divisors is an integer number (169054270).

Almost surely, 2^642406207 is an apocalyptic number.

642406207 is a deficient number, since it is larger than the sum of its proper divisors (33810873).

642406207 is a wasteful number, since it uses less digits than its factorization.

642406207 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33810872.

The product of its (nonzero) digits is 16128, while the sum is 31.

The square root of 642406207 is about 25345.7335068449. The cubic root of 642406207 is about 862.8525286356.

The spelling of 642406207 in words is "six hundred forty-two million, four hundred six thousand, two hundred seven".