13913721 has 8 divisors (see below), whose sum is σ = 20612960. Its totient is φ = 9275796.

The previous prime is 13913693. The next prime is 13913729. The reversal of 13913721 is 12731931.

It is not a de Polignac number, because 13913721 - 2¹⁴ = 13897337 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 515323 = 13913721 / (1 + 3 + 9 + 1 + 3 + 7 + 2 + 1).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13913729) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 257635 + ... + 257688.

It is an arithmetic number, because the mean of its divisors is an integer number (2576620).

Almost surely, 2^13913721 is an apocalyptic number.

It is an amenable number.

13913721 is a deficient number, since it is larger than the sum of its proper divisors (6699239).

13913721 is an equidigital number, since it uses as much as digits as its factorization.

13913721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 515332 (or 515326 counting only the distinct ones).

The product of its digits is 1134, while the sum is 27.

The square root of 13913721 is about 3730.1100519958. The cubic root of 13913721 is about 240.5180994990.

The spelling of 13913721 in words is "thirteen million, nine hundred thirteen thousand, seven hundred twenty-one".