642863787 has 8 divisors (see below), whose sum is σ = 860411904. Its totient is φ = 426945768.

The previous prime is 642863783. The next prime is 642863827. The reversal of 642863787 is 787368246.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 642863787 - 2² = 642863783 is a prime.

It is not an unprimeable number, because it can be changed into a prime (642863783) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 406603 + ... + 408180.

It is an arithmetic number, because the mean of its divisors is an integer number (107551488).

Almost surely, 2^642863787 is an apocalyptic number.

642863787 is a deficient number, since it is larger than the sum of its proper divisors (217548117).

642863787 is a wasteful number, since it uses less digits than its factorization.

642863787 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 815049.

The product of its digits is 2709504, while the sum is 51.

The square root of 642863787 is about 25354.7586657811. The cubic root of 642863787 is about 863.0573473052.

The spelling of 642863787 in words is "six hundred forty-two million, eight hundred sixty-three thousand, seven hundred eighty-seven".