642748918 has 8 divisors (see below), whose sum is σ = 1101855312. Its totient is φ = 275463816.

The previous prime is 642748901. The next prime is 642748921. The reversal of 642748918 is 819847246.

It is a happy number.

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

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 3 ways as a sum of consecutive naturals, for example, 22955305 + ... + 22955332.

It is an arithmetic number, because the mean of its divisors is an integer number (137731914).

Almost surely, 2^642748918 is an apocalyptic number.

642748918 is a deficient number, since it is larger than the sum of its proper divisors (459106394).

642748918 is a wasteful number, since it uses less digits than its factorization.

642748918 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45910646.

The product of its digits is 774144, while the sum is 49.

The square root of 642748918 is about 25352.4933290594. The cubic root of 642748918 is about 863.0059396084.

The spelling of 642748918 in words is "six hundred forty-two million, seven hundred forty-eight thousand, nine hundred eighteen".