13639618420 has 24 divisors (see below), whose sum is σ = 29341815048. Its totient is φ = 5322777600.

The previous prime is 13639618417. The next prime is 13639618429. The reversal of 13639618420 is 2481693631.

It can be written as a sum of positive squares in 4 ways, for example, as 678706704 + 12960911716 = 26052^2 + 113846^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13639618429) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8316021 + ... + 8317660.

It is an arithmetic number, because the mean of its divisors is an integer number (1222575627).

Almost surely, 2^13639618420 is an apocalyptic number.

13639618420 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

13639618420 is an abundant number, since it is smaller than the sum of its proper divisors (15702196628).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

13639618420 is a wasteful number, since it uses less digits than its factorization.

13639618420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16633731 (or 16633729 counting only the distinct ones).

The product of its (nonzero) digits is 186624, while the sum is 43.

The spelling of 13639618420 in words is "thirteen billion, six hundred thirty-nine million, six hundred eighteen thousand, four hundred twenty".