639880379269 has 8 divisors (see below), whose sum is σ = 642999956760. Its totient is φ = 636768384000.

The previous prime is 639880379251. The next prime is 639880379351. The reversal of 639880379269 is 962973088936.

It can be written as a sum of positive squares in 4 ways, for example, as 23820218244 + 616060161025 = 154338^2 + 784895^2 .

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 639880379269 - 2⁹ = 639880378757 is a prime.

It is a super-2 number, since 2×639880379269² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 639880379198 and 639880379207.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639880379209) 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, 1726324 + ... + 2063965.

It is an arithmetic number, because the mean of its divisors is an integer number (80374994595).

Almost surely, 2^639880379269 is an apocalyptic number.

It is an amenable number.

639880379269 is a deficient number, since it is larger than the sum of its proper divisors (3119577491).

639880379269 is a wasteful number, since it uses less digits than its factorization.

639880379269 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3791111.

The product of its (nonzero) digits is 211631616, while the sum is 70.

The spelling of 639880379269 in words is "six hundred thirty-nine billion, eight hundred eighty million, three hundred seventy-nine thousand, two hundred sixty-nine".