642159698 has 4 divisors (see below), whose sum is σ = 963239550. Its totient is φ = 321079848.

The previous prime is 642159659. The next prime is 642159709. The reversal of 642159698 is 896951246.

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

It can be written as a sum of positive squares in only one way, i.e., 570875449 + 71284249 = 23893^2 + 8443^2 .

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160539923 + ... + 160539926.

Almost surely, 2^642159698 is an apocalyptic number.

642159698 is a deficient number, since it is larger than the sum of its proper divisors (321079852).

642159698 is a wasteful number, since it uses less digits than its factorization.

642159698 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 321079851.

The product of its digits is 933120, while the sum is 50.

The square root of 642159698 is about 25340.8701113438. The cubic root of 642159698 is about 862.7421477354.

The spelling of 642159698 in words is "six hundred forty-two million, one hundred fifty-nine thousand, six hundred ninety-eight".