642655201 has 4 divisors (see below), whose sum is σ = 643674304. Its totient is φ = 641636100.

The previous prime is 642655193. The next prime is 642655207. The reversal of 642655201 is 102556246.

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 not a de Polignac number, because 642655201 - 2³ = 642655193 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (642655207) 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, 508605 + ... + 509866.

It is an arithmetic number, because the mean of its divisors is an integer number (160918576).

Almost surely, 2^642655201 is an apocalyptic number.

It is an amenable number.

642655201 is a deficient number, since it is larger than the sum of its proper divisors (1019103).

642655201 is a wasteful number, since it uses less digits than its factorization.

642655201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1019102.

The product of its (nonzero) digits is 14400, while the sum is 31.

The square root of 642655201 is about 25350.6449819329. The cubic root of 642655201 is about 862.9639935978.

The spelling of 642655201 in words is "six hundred forty-two million, six hundred fifty-five thousand, two hundred one".