642688498 has 4 divisors (see below), whose sum is σ = 964032750. Its totient is φ = 321344248.

The previous prime is 642688469. The next prime is 642688513. The reversal of 642688498 is 894886246.

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., 642470409 + 218089 = 25347^2 + 467^2 .

It is a super-2 number, since 2×642688498² = 826097010922992008, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160672123 + ... + 160672126.

Almost surely, 2^642688498 is an apocalyptic number.

642688498 is a deficient number, since it is larger than the sum of its proper divisors (321344252).

642688498 is a wasteful number, since it uses less digits than its factorization.

642688498 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 321344251.

The product of its digits is 5308416, while the sum is 55.

The square root of 642688498 is about 25351.3017022795. The cubic root of 642688498 is about 862.9788971914.

The spelling of 642688498 in words is "six hundred forty-two million, six hundred eighty-eight thousand, four hundred ninety-eight".