638983021709 has 16 divisors (see below), whose sum is σ = 683823942144. Its totient is φ = 596019820800.

The previous prime is 638983021697. The next prime is 638983021751. The reversal of 638983021709 is 907120389836.

It is not a de Polignac number, because 638983021709 - 2¹⁶ = 638982956173 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638983021769) 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, 2923064 + ... + 3134049.

It is an arithmetic number, because the mean of its divisors is an integer number (42738996384).

Almost surely, 2^638983021709 is an apocalyptic number.

It is an amenable number.

638983021709 is a deficient number, since it is larger than the sum of its proper divisors (44840920435).

638983021709 is a wasteful number, since it uses less digits than its factorization.

638983021709 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6057268.

The product of its (nonzero) digits is 3919104, while the sum is 56.

The spelling of 638983021709 in words is "six hundred thirty-eight billion, nine hundred eighty-three million, twenty-one thousand, seven hundred nine".