642261089 has 4 divisors (see below), whose sum is σ = 642713856. Its totient is φ = 641808324.

The previous prime is 642261043. The next prime is 642261097. The reversal of 642261089 is 980162246.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-642261089 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (642260089) 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, 224249 + ... + 227094.

It is an arithmetic number, because the mean of its divisors is an integer number (160678464).

Almost surely, 2^642261089 is an apocalyptic number.

It is an amenable number.

642261089 is a deficient number, since it is larger than the sum of its proper divisors (452767).

642261089 is a wasteful number, since it uses less digits than its factorization.

642261089 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 452766.

The product of its (nonzero) digits is 41472, while the sum is 38.

The square root of 642261089 is about 25342.8705753709. The cubic root of 642261089 is about 862.7875516466.

The spelling of 642261089 in words is "six hundred forty-two million, two hundred sixty-one thousand, eighty-nine".