13900805 has 4 divisors (see below), whose sum is σ = 16680972. Its totient is φ = 11120640.

The previous prime is 13900793. The next prime is 13900807. The reversal of 13900805 is 50800931.

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 2617924 + 11282881 = 1618^2 + 3359^2 .

It is not a de Polignac number, because 13900805 - 2¹⁸ = 13638661 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13900807) 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, 1390076 + ... + 1390085.

It is an arithmetic number, because the mean of its divisors is an integer number (4170243).

Almost surely, 2^13900805 is an apocalyptic number.

It is an amenable number.

13900805 is a deficient number, since it is larger than the sum of its proper divisors (2780167).

13900805 is an equidigital number, since it uses as much as digits as its factorization.

13900805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2780166.

The product of its (nonzero) digits is 1080, while the sum is 26.

The square root of 13900805 is about 3728.3783338068. The cubic root of 13900805 is about 240.4436527586.

The spelling of 13900805 in words is "thirteen million, nine hundred thousand, eight hundred five".