13899805 has 4 divisors (see below), whose sum is σ = 16679772. Its totient is φ = 11119840.

The previous prime is 13899803. The next prime is 13899839. The reversal of 13899805 is 50899831.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 7458361 + 6441444 = 2731^2 + 2538^2 .

It is not a de Polignac number, because 13899805 - 2¹ = 13899803 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 (13899803) 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, 1389976 + ... + 1389985.

It is an arithmetic number, because the mean of its divisors is an integer number (4169943).

Almost surely, 2^13899805 is an apocalyptic number.

It is an amenable number.

13899805 is a deficient number, since it is larger than the sum of its proper divisors (2779967).

13899805 is an equidigital number, since it uses as much as digits as its factorization.

13899805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2779966.

The product of its (nonzero) digits is 77760, while the sum is 43.

The square root of 13899805 is about 3728.2442248329. The cubic root of 13899805 is about 240.4378869194.

The spelling of 13899805 in words is "thirteen million, eight hundred ninety-nine thousand, eight hundred five".