13731994 has 4 divisors (see below), whose sum is σ = 20597994. Its totient is φ = 6865996.

The previous prime is 13731983. The next prime is 13732001. The reversal of 13731994 is 49913731.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 49913731 = 7 ⋅7130533.

It can be written as a sum of positive squares in only one way, i.e., 12075625 + 1656369 = 3475^2 + 1287^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3432997 + ... + 3433000.

Almost surely, 2^13731994 is an apocalyptic number.

13731994 is a deficient number, since it is larger than the sum of its proper divisors (6866000).

13731994 is an equidigital number, since it uses as much as digits as its factorization.

13731994 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6865999.

The product of its digits is 20412, while the sum is 37.

The square root of 13731994 is about 3705.6705196226. The cubic root of 13731994 is about 239.4663722557.

It can be divided in two parts, 137 and 31994, that added together give a triangular number (32131 = T₂₅₃).

The spelling of 13731994 in words is "thirteen million, seven hundred thirty-one thousand, nine hundred ninety-four".