642118591 has 8 divisors (see below), whose sum is σ = 647281664. Its totient is φ = 636967800.

The previous prime is 642118579. The next prime is 642118597. The reversal of 642118591 is 195811246.

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 642118591 - 2⁹ = 642118079 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 642118591.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642118597) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 121690 + ... + 126856.

It is an arithmetic number, because the mean of its divisors is an integer number (80910208).

Almost surely, 2^642118591 is an apocalyptic number.

642118591 is a deficient number, since it is larger than the sum of its proper divisors (5163073).

642118591 is a wasteful number, since it uses less digits than its factorization.

642118591 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6141.

The product of its digits is 17280, while the sum is 37.

The square root of 642118591 is about 25340.0590172951. The cubic root of 642118591 is about 862.7237382451.

The spelling of 642118591 in words is "six hundred forty-two million, one hundred eighteen thousand, five hundred ninety-one".