13722640 has 40 divisors (see below), whose sum is σ = 32062680. Its totient is φ = 5462016.

The previous prime is 13722629. The next prime is 13722647. The reversal of 13722640 is 4622731.

It can be written as a sum of positive squares in 4 ways, for example, as 1806336 + 11916304 = 1344^2 + 3452^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is not an unprimeable number, because it can be changed into a prime (13722647) 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, 26706 + ... + 27214.

It is an arithmetic number, because the mean of its divisors is an integer number (801567).

Almost surely, 2^13722640 is an apocalyptic number.

13722640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

13722640 is an abundant number, since it is smaller than the sum of its proper divisors (18340040).

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

13722640 is a wasteful number, since it uses less digits than its factorization.

13722640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 859 (or 853 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 25.

The square root of 13722640 is about 3704.4081848522. The cubic root of 13722640 is about 239.4119864360.

Subtracting from 13722640 its reverse (4622731), we obtain a palindrome (9099909).

The spelling of 13722640 in words is "thirteen million, seven hundred twenty-two thousand, six hundred forty".