642428867 has 4 divisors (see below), whose sum is σ = 644031336. Its totient is φ = 640826400.

The previous prime is 642428863. The next prime is 642428873. The reversal of 642428867 is 768824246.

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 642428867 - 2² = 642428863 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (642428863) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 800633 + ... + 801434.

It is an arithmetic number, because the mean of its divisors is an integer number (161007834).

Almost surely, 2^642428867 is an apocalyptic number.

642428867 is a deficient number, since it is larger than the sum of its proper divisors (1602469).

642428867 is a wasteful number, since it uses less digits than its factorization.

642428867 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1602468.

The product of its digits is 1032192, while the sum is 47.

The square root of 642428867 is about 25346.1805209385. The cubic root of 642428867 is about 862.8626738304.

The spelling of 642428867 in words is "six hundred forty-two million, four hundred twenty-eight thousand, eight hundred sixty-seven".