642500871 has 4 divisors (see below), whose sum is σ = 856667832. Its totient is φ = 428333912.

The previous prime is 642500869. The next prime is 642500891. The reversal of 642500871 is 178005246.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 642500871 - 2¹ = 642500869 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642500891) 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, 107083476 + ... + 107083481.

It is an arithmetic number, because the mean of its divisors is an integer number (214166958).

Almost surely, 2^642500871 is an apocalyptic number.

642500871 is a deficient number, since it is larger than the sum of its proper divisors (214166961).

642500871 is a wasteful number, since it uses less digits than its factorization.

642500871 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 214166960.

The product of its (nonzero) digits is 13440, while the sum is 33.

The square root of 642500871 is about 25347.6008923922. The cubic root of 642500871 is about 862.8949094320.

The spelling of 642500871 in words is "six hundred forty-two million, five hundred thousand, eight hundred seventy-one".