642690766 has 16 divisors (see below), whose sum is σ = 976656240. Its totient is φ = 317157120.

The previous prime is 642690757. The next prime is 642690787. The reversal of 642690766 is 667096246.

It is a congruent number.

It is an unprimeable number.

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, 69156 + ... + 77896.

It is an arithmetic number, because the mean of its divisors is an integer number (61041015).

Almost surely, 2^642690766 is an apocalyptic number.

642690766 is a deficient number, since it is larger than the sum of its proper divisors (333965474).

642690766 is a wasteful number, since it uses less digits than its factorization.

642690766 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9219.

The product of its (nonzero) digits is 653184, while the sum is 46.

The square root of 642690766 is about 25351.3464336709. The cubic root of 642690766 is about 862.9799123197.

The spelling of 642690766 in words is "six hundred forty-two million, six hundred ninety thousand, seven hundred sixty-six".