639795919 has 8 divisors (see below), whose sum is σ = 731354240. Its totient is φ = 548277336.

The previous prime is 639795917. The next prime is 639795953. The reversal of 639795919 is 919597936.

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

It is a cyclic number.

It is not a de Polignac number, because 639795919 - 2¹ = 639795917 is a prime.

It is a super-2 number, since 2×639795919² = 818677635938109122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639795917) 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 7 ways as a sum of consecutive naturals, for example, 44392 + ... + 57010.

It is an arithmetic number, because the mean of its divisors is an integer number (91419280).

Almost surely, 2^639795919 is an apocalyptic number.

639795919 is a deficient number, since it is larger than the sum of its proper divisors (91558321).

639795919 is a wasteful number, since it uses less digits than its factorization.

639795919 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19869.

The product of its digits is 4133430, while the sum is 58.

The square root of 639795919 is about 25294.1874548284. The cubic root of 639795919 is about 861.6822664443.

The spelling of 639795919 in words is "six hundred thirty-nine million, seven hundred ninety-five thousand, nine hundred nineteen".