13793781 has 4 divisors (see below), whose sum is σ = 18391712. Its totient is φ = 9195852.

The previous prime is 13793777. The next prime is 13793789. The reversal of 13793781 is 18739731.

It is a happy number.

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, and also an emirpimes, since its reverse is a distinct semiprime: 18739731 = 3 ⋅6246577.

It is not a de Polignac number, because 13793781 - 2² = 13793777 is a prime.

It is a super-2 number, since 2×13793781² = 380536788551922, 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 (13793789) 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, 2298961 + ... + 2298966.

It is an arithmetic number, because the mean of its divisors is an integer number (4597928).

Almost surely, 2^13793781 is an apocalyptic number.

It is an amenable number.

13793781 is a deficient number, since it is larger than the sum of its proper divisors (4597931).

13793781 is an equidigital number, since it uses as much as digits as its factorization.

13793781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4597930.

The product of its digits is 31752, while the sum is 39.

The square root of 13793781 is about 3713.9979806133. The cubic root of 13793781 is about 239.8249939458.

The spelling of 13793781 in words is "thirteen million, seven hundred ninety-three thousand, seven hundred eighty-one".