13925721 has 4 divisors (see below), whose sum is σ = 18567632. Its totient is φ = 9283812.

The previous prime is 13925701. The next prime is 13925753. The reversal of 13925721 is 12752931.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 12752931 = 3 ⋅4250977.

It is not a de Polignac number, because 13925721 - 2¹¹ = 13923673 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13925701) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2320951 + ... + 2320956.

It is an arithmetic number, because the mean of its divisors is an integer number (4641908).

Almost surely, 2^13925721 is an apocalyptic number.

It is an amenable number.

13925721 is a deficient number, since it is larger than the sum of its proper divisors (4641911).

13925721 is an equidigital number, since it uses as much as digits as its factorization.

13925721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4641910.

The product of its digits is 3780, while the sum is 30.

The square root of 13925721 is about 3731.7182369520. The cubic root of 13925721 is about 240.5872252165.

The spelling of 13925721 in words is "thirteen million, nine hundred twenty-five thousand, seven hundred twenty-one".