639791026 has 8 divisors (see below), whose sum is σ = 1096784640. Its totient is φ = 274196148.

The previous prime is 639791021. The next prime is 639791027. The reversal of 639791026 is 620197936.

639791026 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is not an unprimeable number, because it can be changed into a prime (639791021) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22849666 + ... + 22849693.

It is an arithmetic number, because the mean of its divisors is an integer number (137098080).

Almost surely, 2^639791026 is an apocalyptic number.

639791026 is a deficient number, since it is larger than the sum of its proper divisors (456993614).

639791026 is a wasteful number, since it uses less digits than its factorization.

639791026 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45699368.

The product of its (nonzero) digits is 122472, while the sum is 43.

The square root of 639791026 is about 25294.0907328174. The cubic root of 639791026 is about 861.6800697948.

It can be divided in two parts, 6397910 and 26, that added together give a palindrome (6397936).

The spelling of 639791026 in words is "six hundred thirty-nine million, seven hundred ninety-one thousand, twenty-six".