13661491 has 2 divisors, whose sum is σ = 13661492. Its totient is φ = 13661490.

The previous prime is 13661467. The next prime is 13661497. The reversal of 13661491 is 19416631.

13661491 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 13661491 - 2²¹ = 11564339 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (13661497) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6830745 + 6830746.

It is an arithmetic number, because the mean of its divisors is an integer number (6830746).

Almost surely, 2^13661491 is an apocalyptic number.

13661491 is a deficient number, since it is larger than the sum of its proper divisors (1).

13661491 is an equidigital number, since it uses as much as digits as its factorization.

13661491 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3888, while the sum is 31.

The square root of 13661491 is about 3696.1454246282. The cubic root of 13661491 is about 239.0558449826.

The spelling of 13661491 in words is "thirteen million, six hundred sixty-one thousand, four hundred ninety-one".