642847659 has 4 divisors (see below), whose sum is σ = 857130216. Its totient is φ = 428565104.

The previous prime is 642847643. The next prime is 642847663. The reversal of 642847659 is 956748246.

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 642847659 - 2⁴ = 642847643 is a prime.

It is a super-2 number, since 2×642847659² = 826506225363560562, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (642847679) 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, 107141274 + ... + 107141279.

It is an arithmetic number, because the mean of its divisors is an integer number (214282554).

Almost surely, 2^642847659 is an apocalyptic number.

642847659 is a deficient number, since it is larger than the sum of its proper divisors (214282557).

642847659 is a wasteful number, since it uses less digits than its factorization.

642847659 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 214282556.

The product of its digits is 2903040, while the sum is 51.

The square root of 642847659 is about 25354.4406169807. The cubic root of 642847659 is about 863.0501298585.

The spelling of 642847659 in words is "six hundred forty-two million, eight hundred forty-seven thousand, six hundred fifty-nine".