13639891 has 8 divisors (see below), whose sum is σ = 14487120. Its totient is φ = 12805632.

The previous prime is 13639867. The next prime is 13639919. The reversal of 13639891 is 19893631.

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 13639891 - 2⁵ = 13639859 is a prime.

It is not an unprimeable number, because it can be changed into a prime (13639811) 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, 1030 + ... + 5323.

It is an arithmetic number, because the mean of its divisors is an integer number (1810890).

Almost surely, 2^13639891 is an apocalyptic number.

13639891 is a deficient number, since it is larger than the sum of its proper divisors (847229).

13639891 is a wasteful number, since it uses less digits than its factorization.

13639891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6485.

The product of its digits is 34992, while the sum is 40.

The square root of 13639891 is about 3693.2223057921. Note that the first 3 decimals coincide. The cubic root of 13639891 is about 238.9297891952.

The spelling of 13639891 in words is "thirteen million, six hundred thirty-nine thousand, eight hundred ninety-one".