13721391680 has 28 divisors (see below), whose sum is σ = 32674064700. Its totient is φ = 5488556544.

The previous prime is 13721391659. The next prime is 13721391701. The reversal of 13721391680 is 8619312731.

It is an interprime number because it is at equal distance from previous prime (13721391659) and next prime (13721391701).

It can be written as a sum of positive squares in 2 ways, for example, as 3270009856 + 10451381824 = 57184^2 + 102232^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21439355 + ... + 21439994.

Almost surely, 2^13721391680 is an apocalyptic number.

13721391680 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

13721391680 is an abundant number, since it is smaller than the sum of its proper divisors (18952673020).

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

13721391680 is an equidigital number, since it uses as much as digits as its factorization.

13721391680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42879366 (or 42879356 counting only the distinct ones).

The product of its (nonzero) digits is 54432, while the sum is 41.

The spelling of 13721391680 in words is "thirteen billion, seven hundred twenty-one million, three hundred ninety-one thousand, six hundred eighty".