13999639 has 8 divisors (see below), whose sum is σ = 14402432. Its totient is φ = 13600440.

The previous prime is 13999621. The next prime is 13999651. The reversal of 13999639 is 93699931.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 13999639 - 2¹⁷ = 13868567 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 13999592 and 13999601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13991639) 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, 8302 + ... + 9844.

It is an arithmetic number, because the mean of its divisors is an integer number (1800304).

Almost surely, 2^13999639 is an apocalyptic number.

13999639 is a deficient number, since it is larger than the sum of its proper divisors (402793).

13999639 is a wasteful number, since it uses less digits than its factorization.

13999639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1797.

The product of its digits is 354294, while the sum is 49.

The square root of 13999639 is about 3741.6091458088. The cubic root of 13999639 is about 241.0121548251.

The spelling of 13999639 in words is "thirteen million, nine hundred ninety-nine thousand, six hundred thirty-nine".