642591259 has 4 divisors (see below), whose sum is σ = 642658680. Its totient is φ = 642523840.

The previous prime is 642591241. The next prime is 642591283. The reversal of 642591259 is 952195246.

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 a de Polignac number, because none of the positive numbers 2^k-642591259 is a prime.

It is a super-2 number, since 2×642591259² = 825847052286410162, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (642591359) 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, 16477 + ... + 39454.

It is an arithmetic number, because the mean of its divisors is an integer number (160664670).

Almost surely, 2^642591259 is an apocalyptic number.

642591259 is a deficient number, since it is larger than the sum of its proper divisors (67421).

642591259 is a wasteful number, since it uses less digits than its factorization.

642591259 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67420.

The product of its digits is 194400, while the sum is 43.

The square root of 642591259 is about 25349.3837992169. The cubic root of 642591259 is about 862.9353719908.

The spelling of 642591259 in words is "six hundred forty-two million, five hundred ninety-one thousand, two hundred fifty-nine".