13909621 has 8 divisors (see below), whose sum is σ = 16066944. Its totient is φ = 11901120.

The previous prime is 13909601. The next prime is 13909627. The reversal of 13909621 is 12690931.

13909621 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 13909621 - 2⁹ = 13909109 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13909627) 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, 37005 + ... + 37378.

It is an arithmetic number, because the mean of its divisors is an integer number (2008368).

Almost surely, 2^13909621 is an apocalyptic number.

13909621 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

13909621 is a deficient number, since it is larger than the sum of its proper divisors (2157323).

13909621 is a wasteful number, since it uses less digits than its factorization.

13909621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74411.

The product of its (nonzero) digits is 2916, while the sum is 31.

The square root of 13909621 is about 3729.5604298630. The cubic root of 13909621 is about 240.4944724360.

It can be divided in two parts, 1390 and 9621, that added together give a palindrome (11011).

The spelling of 13909621 in words is "thirteen million, nine hundred nine thousand, six hundred twenty-one".