13981605 has 16 divisors (see below), whose sum is σ = 24404544. Its totient is φ = 6778880.

The previous prime is 13981601. The next prime is 13981619. The reversal of 13981605 is 50618931.

It is not a de Polignac number, because 13981605 - 2² = 13981601 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13981601) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 42204 + ... + 42533.

It is an arithmetic number, because the mean of its divisors is an integer number (1525284).

Almost surely, 2^13981605 is an apocalyptic number.

13981605 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

13981605 is a deficient number, since it is larger than the sum of its proper divisors (10422939).

13981605 is a wasteful number, since it uses less digits than its factorization.

13981605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84756.

The product of its (nonzero) digits is 6480, while the sum is 33.

The square root of 13981605 is about 3739.1984435170. The cubic root of 13981605 is about 240.9086216589.

It can be divided in two parts, 1398 and 1605, that added together give a palindrome (3003).

The spelling of 13981605 in words is "thirteen million, nine hundred eighty-one thousand, six hundred five".