13907981 has 4 divisors (see below), whose sum is σ = 14640000. Its totient is φ = 13175964.

The previous prime is 13907953. The next prime is 13907983. The reversal of 13907981 is 18970931.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 13907981 - 2¹⁸ = 13645837 is a prime.

It is a super-2 number, since 2×13907981² = 386863870992722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13907983) 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, 365981 + ... + 366018.

It is an arithmetic number, because the mean of its divisors is an integer number (3660000).

Almost surely, 2^13907981 is an apocalyptic number.

It is an amenable number.

13907981 is a deficient number, since it is larger than the sum of its proper divisors (732019).

13907981 is an equidigital number, since it uses as much as digits as its factorization.

13907981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 732018.

The product of its (nonzero) digits is 13608, while the sum is 38.

The square root of 13907981 is about 3729.3405583293. The cubic root of 13907981 is about 240.4850203109.

The spelling of 13907981 in words is "thirteen million, nine hundred seven thousand, nine hundred eighty-one".