13781091 has 12 divisors (see below), whose sum is σ = 18597768. Its totient is φ = 9077184.

The previous prime is 13781087. The next prime is 13781107. The reversal of 13781091 is 19018731.

It is not a de Polignac number, because 13781091 - 2² = 13781087 is a prime.

It is not an unprimeable number, because it can be changed into a prime (13781041) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 31611 + ... + 32043.

It is an arithmetic number, because the mean of its divisors is an integer number (1549814).

Almost surely, 2^13781091 is an apocalyptic number.

13781091 is a deficient number, since it is larger than the sum of its proper divisors (4816677).

13781091 is an equidigital number, since it uses as much as digits as its factorization.

13781091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 642 (or 539 counting only the distinct ones).

The product of its (nonzero) digits is 1512, while the sum is 30.

The square root of 13781091 is about 3712.2891859337. The cubic root of 13781091 is about 239.7514266637.

The spelling of 13781091 in words is "thirteen million, seven hundred eighty-one thousand, ninety-one".