642591223 has 4 divisors (see below), whose sum is σ = 642651208. Its totient is φ = 642531240.

The previous prime is 642591199. The next prime is 642591241. The reversal of 642591223 is 322195246.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 642591223 - 2²⁹ = 105720311 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 (642591283) 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, 9048 + ... + 36973.

It is an arithmetic number, because the mean of its divisors is an integer number (160662802).

Almost surely, 2^642591223 is an apocalyptic number.

642591223 is a deficient number, since it is larger than the sum of its proper divisors (59985).

642591223 is a wasteful number, since it uses less digits than its factorization.

642591223 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 59984.

The product of its digits is 25920, while the sum is 34.

The square root of 642591223 is about 25349.3830891405. The cubic root of 642591223 is about 862.9353558760.

The spelling of 642591223 in words is "six hundred forty-two million, five hundred ninety-one thousand, two hundred twenty-three".