642977999 has 8 divisors (see below), whose sum is σ = 652565760. Its totient is φ = 633461400.

The previous prime is 642977989. The next prime is 642978043. The reversal of 642977999 is 999779246.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 642977999 - 2⁸ = 642977743 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 (642977939) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 554 + ... + 35864.

It is an arithmetic number, because the mean of its divisors is an integer number (81570720).

Almost surely, 2^642977999 is an apocalyptic number.

642977999 is a deficient number, since it is larger than the sum of its proper divisors (9587761).

642977999 is a wasteful number, since it uses less digits than its factorization.

642977999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35581.

The product of its digits is 15431472, while the sum is 62.

The square root of 642977999 is about 25357.0108451292. The cubic root of 642977999 is about 863.1084549015.

The spelling of 642977999 in words is "six hundred forty-two million, nine hundred seventy-seven thousand, nine hundred ninety-nine".