642640263 has 8 divisors (see below), whose sum is σ = 894108288. Its totient is φ = 409799544.

The previous prime is 642640189. The next prime is 642640279. The reversal of 642640263 is 362046246.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 642640263 - 2⁸ = 642640007 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642640283) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4656745 + ... + 4656882.

It is an arithmetic number, because the mean of its divisors is an integer number (111763536).

Almost surely, 2^642640263 is an apocalyptic number.

642640263 is a deficient number, since it is larger than the sum of its proper divisors (251468025).

642640263 is a wasteful number, since it uses less digits than its factorization.

642640263 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9313653.

The product of its (nonzero) digits is 41472, while the sum is 33.

The square root of 642640263 is about 25350.3503526085. The cubic root of 642640263 is about 862.9573072461.

The spelling of 642640263 in words is "six hundred forty-two million, six hundred forty thousand, two hundred sixty-three".