639873474 has 8 divisors (see below), whose sum is σ = 1279746960. Its totient is φ = 213291156.

The previous prime is 639873473. The next prime is 639873581. The reversal of 639873474 is 474378936.

It is a happy number.

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

639873474 is an admirable number.

It is not an unprimeable number, because it can be changed into a prime (639873473) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 53322784 + ... + 53322795.

It is an arithmetic number, because the mean of its divisors is an integer number (159968370).

Almost surely, 2^639873474 is an apocalyptic number.

639873474 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

639873474 is a wasteful number, since it uses less digits than its factorization.

639873474 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106645584.

The product of its digits is 3048192, while the sum is 51.

The square root of 639873474 is about 25295.7204680950. The cubic root of 639873474 is about 861.7170822692.

The spelling of 639873474 in words is "six hundred thirty-nine million, eight hundred seventy-three thousand, four hundred seventy-four".