639950070821 has 16 divisors (see below), whose sum is σ = 682999050240. Its totient is φ = 597518833920.

The previous prime is 639950070733. The next prime is 639950070883. The reversal of 639950070821 is 128070059936.

It is a cyclic number.

It is not a de Polignac number, because 639950070821 - 2¹⁰ = 639950069797 is a prime.

It is a super-3 number, since 3×639950070821³ (a number of 36 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a self number, because there is not a number n which added to its sum of digits gives 639950070821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639950072821) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 923135 + ... + 1460163.

It is an arithmetic number, because the mean of its divisors is an integer number (42687440640).

Almost surely, 2^639950070821 is an apocalyptic number.

It is an amenable number.

639950070821 is a deficient number, since it is larger than the sum of its proper divisors (43048979419).

639950070821 is a wasteful number, since it uses less digits than its factorization.

639950070821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 537604.

The product of its (nonzero) digits is 816480, while the sum is 50.

The spelling of 639950070821 in words is "six hundred thirty-nine billion, nine hundred fifty million, seventy thousand, eight hundred twenty-one".