642255249 has 4 divisors (see below), whose sum is σ = 856340336. Its totient is φ = 428170164.

The previous prime is 642255221. The next prime is 642255253. The reversal of 642255249 is 942552246.

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 not a de Polignac number, because 642255249 - 2⁵ = 642255217 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (642255259) 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, 107042539 + ... + 107042544.

It is an arithmetic number, because the mean of its divisors is an integer number (214085084).

Almost surely, 2^642255249 is an apocalyptic number.

It is an amenable number.

642255249 is a deficient number, since it is larger than the sum of its proper divisors (214085087).

642255249 is a wasteful number, since it uses less digits than its factorization.

642255249 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 214085086.

The product of its digits is 172800, while the sum is 39.

The square root of 642255249 is about 25342.7553553279. The cubic root of 642255249 is about 862.7849365655.

The spelling of 642255249 in words is "six hundred forty-two million, two hundred fifty-five thousand, two hundred forty-nine".