642689499 has 8 divisors (see below), whose sum is σ = 857124352. Its totient is φ = 428357160.

The previous prime is 642689479. The next prime is 642689521. The reversal of 642689499 is 994986246.

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

It is not a de Polignac number, because 642689499 - 2⁹ = 642688987 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (642689479) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9559 + ... + 37104.

It is an arithmetic number, because the mean of its divisors is an integer number (107140544).

Almost surely, 2^642689499 is an apocalyptic number.

642689499 is a deficient number, since it is larger than the sum of its proper divisors (214434853).

642689499 is a wasteful number, since it uses less digits than its factorization.

642689499 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51257.

The product of its digits is 6718464, while the sum is 57.

The square root of 642689499 is about 25351.3214448478. The cubic root of 642689499 is about 862.9793452267.

The spelling of 642689499 in words is "six hundred forty-two million, six hundred eighty-nine thousand, four hundred ninety-nine".