639671793 has 8 divisors (see below), whose sum is σ = 853546656. Its totient is φ = 426122400.

The previous prime is 639671783. The next prime is 639671807. The reversal of 639671793 is 397176936.

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

It is not a de Polignac number, because 639671793 - 2¹³ = 639663601 is a prime.

It is not an unprimeable number, because it can be changed into a prime (639671723) 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, 76743 + ... + 84668.

It is an arithmetic number, because the mean of its divisors is an integer number (106693332).

Almost surely, 2^639671793 is an apocalyptic number.

It is an amenable number.

639671793 is a deficient number, since it is larger than the sum of its proper divisors (213874863).

639671793 is a wasteful number, since it uses less digits than its factorization.

639671793 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 162735.

The product of its digits is 1285956, while the sum is 51.

The square root of 639671793 is about 25291.7336890930. The cubic root of 639671793 is about 861.6265382100.

The spelling of 639671793 in words is "six hundred thirty-nine million, six hundred seventy-one thousand, seven hundred ninety-three".