642863791 has 8 divisors (see below), whose sum is σ = 657226944. Its totient is φ = 628529280.

The previous prime is 642863783. The next prime is 642863827. The reversal of 642863791 is 197368246.

642863791 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is not a de Polignac number, because 642863791 - 2³ = 642863783 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642863701) 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, 41931 + ... + 55171.

It is an arithmetic number, because the mean of its divisors is an integer number (82153368).

Almost surely, 2^642863791 is an apocalyptic number.

642863791 is a deficient number, since it is larger than the sum of its proper divisors (14363153).

642863791 is a wasteful number, since it uses less digits than its factorization.

642863791 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14321.

The product of its digits is 435456, while the sum is 46.

The square root of 642863791 is about 25354.7587446617. The cubic root of 642863791 is about 863.0573490952.

The spelling of 642863791 in words is "six hundred forty-two million, eight hundred sixty-three thousand, seven hundred ninety-one".