13937721 has 16 divisors (see below), whose sum is σ = 21436800. Its totient is φ = 7890048.

The previous prime is 13937699. The next prime is 13937741. The reversal of 13937721 is 12773931.

It is a happy number.

13937721 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 13937721 - 2⁶ = 13937657 is a prime.

It is not an unprimeable number, because it can be changed into a prime (13937741) 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, 756 + ... + 5333.

It is an arithmetic number, because the mean of its divisors is an integer number (1339800).

Almost surely, 2^13937721 is an apocalyptic number.

It is an amenable number.

13937721 is a deficient number, since it is larger than the sum of its proper divisors (7499079).

13937721 is a wasteful number, since it uses less digits than its factorization.

13937721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6208.

The product of its digits is 7938, while the sum is 33.

The square root of 13937721 is about 3733.3257291589. The cubic root of 13937721 is about 240.6563112344.

The spelling of 13937721 in words is "thirteen million, nine hundred thirty-seven thousand, seven hundred twenty-one".