11817985 has 16 divisors (see below), whose sum is σ = 14708736. Its totient is φ = 9108288.

The previous prime is 11817983. The next prime is 11817997. The reversal of 11817985 is 58971811.

It is a cyclic number.

It is not a de Polignac number, because 11817985 - 2¹ = 11817983 is a prime.

It is a Duffinian number.

Its product of digits (20160) is a multiple of the sum of its prime divisors (672).

It is not an unprimeable number, because it can be changed into a prime (11817983) 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, 23244 + ... + 23746.

It is an arithmetic number, because the mean of its divisors is an integer number (919296).

Almost surely, 2^11817985 is an apocalyptic number.

It is an amenable number.

11817985 is a deficient number, since it is larger than the sum of its proper divisors (2890751).

11817985 is a wasteful number, since it uses less digits than its factorization.

11817985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 672.

The product of its digits is 20160, while the sum is 40.

The square root of 11817985 is about 3437.7296286939. The cubic root of 11817985 is about 227.7794175747.

The spelling of 11817985 in words is "eleven million, eight hundred seventeen thousand, nine hundred eighty-five".