13115661 has 16 divisors (see below), whose sum is σ = 19032384. Its totient is φ = 7985664.

The previous prime is 13115657. The next prime is 13115677. The reversal of 13115661 is 16651131.

It is not a de Polignac number, because 13115661 - 2² = 13115657 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13115611) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2050 + ... + 5516.

It is an arithmetic number, because the mean of its divisors is an integer number (1189524).

Almost surely, 2^13115661 is an apocalyptic number.

It is an amenable number.

13115661 is a deficient number, since it is larger than the sum of its proper divisors (5916723).

13115661 is a wasteful number, since it uses less digits than its factorization.

13115661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3580.

The product of its digits is 540, while the sum is 24.

The square root of 13115661 is about 3621.5550527363. Note that the first 3 decimals coincide. The cubic root of 13115661 is about 235.8287383834.

Adding to 13115661 its reverse (16651131), we get a palindrome (29766792).

The spelling of 13115661 in words is "thirteen million, one hundred fifteen thousand, six hundred sixty-one".