642515686 has 8 divisors (see below), whose sum is σ = 963897984. Its totient is φ = 321216360.

The previous prime is 642515659. The next prime is 642515689. The reversal of 642515686 is 686515246.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642515689) 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, 5016 + ... + 36196.

It is an arithmetic number, because the mean of its divisors is an integer number (120487248).

Almost surely, 2^642515686 is an apocalyptic number.

642515686 is a deficient number, since it is larger than the sum of its proper divisors (321382298).

642515686 is a wasteful number, since it uses less digits than its factorization.

642515686 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41486.

The product of its digits is 345600, while the sum is 43.

The square root of 642515686 is about 25347.8931274376. The cubic root of 642515686 is about 862.9015416875.

The spelling of 642515686 in words is "six hundred forty-two million, five hundred fifteen thousand, six hundred eighty-six".