642777717 has 8 divisors (see below), whose sum is σ = 876968224. Its totient is φ = 418552848.

The previous prime is 642777713. The next prime is 642777719. The reversal of 642777717 is 717777246.

It is a happy number.

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

It is not a de Polignac number, because 642777717 - 2² = 642777713 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642777713) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2491258 + ... + 2491515.

It is an arithmetic number, because the mean of its divisors is an integer number (109621028).

Almost surely, 2^642777717 is an apocalyptic number.

It is an amenable number.

642777717 is a deficient number, since it is larger than the sum of its proper divisors (234190507).

642777717 is a wasteful number, since it uses less digits than its factorization.

642777717 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4982819.

The product of its digits is 806736, while the sum is 48.

The square root of 642777717 is about 25353.0612944473. The cubic root of 642777717 is about 863.0188286937.

The spelling of 642777717 in words is "six hundred forty-two million, seven hundred seventy-seven thousand, seven hundred seventeen".