13997989 has 4 divisors (see below), whose sum is σ = 14262156. Its totient is φ = 13733824.

The previous prime is 13997983. The next prime is 13997993. The reversal of 13997989 is 98979931.

13997989 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 98979931 = 31 ⋅3192901.

It can be written as a sum of positive squares in 2 ways, for example, as 4169764 + 9828225 = 2042^2 + 3135^2 .

It is a cyclic number.

It is not a de Polignac number, because 13997989 - 2⁷ = 13997861 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 (13997983) 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, 132004 + ... + 132109.

It is an arithmetic number, because the mean of its divisors is an integer number (3565539).

Almost surely, 2^13997989 is an apocalyptic number.

It is an amenable number.

13997989 is a deficient number, since it is larger than the sum of its proper divisors (264167).

13997989 is an equidigital number, since it uses as much as digits as its factorization.

13997989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 264166.

The product of its digits is 1102248, while the sum is 55.

The square root of 13997989 is about 3741.3886459442. The cubic root of 13997989 is about 241.0026858742.

The spelling of 13997989 in words is "thirteen million, nine hundred ninety-seven thousand, nine hundred eighty-nine".