13699921 has 2 divisors, whose sum is σ = 13699922. Its totient is φ = 13699920.

The previous prime is 13699853. The next prime is 13699949. The reversal of 13699921 is 12999631.

13699921 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7349521 + 6350400 = 2711^2 + 2520^2 .

It is a cyclic number.

It is not a de Polignac number, because 13699921 - 2⁷ = 13699793 is a prime.

It is not a weakly prime, because it can be changed into another prime (13699981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6849960 + 6849961.

It is an arithmetic number, because the mean of its divisors is an integer number (6849961).

Almost surely, 2^13699921 is an apocalyptic number.

It is an amenable number.

13699921 is a deficient number, since it is larger than the sum of its proper divisors (1).

13699921 is an equidigital number, since it uses as much as digits as its factorization.

13699921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 26244, while the sum is 40.

The square root of 13699921 is about 3701.3404328702. The cubic root of 13699921 is about 239.2797911400.

The spelling of 13699921 in words is "thirteen million, six hundred ninety-nine thousand, nine hundred twenty-one".