11817987 has 8 divisors (see below), whose sum is σ = 15787200. Its totient is φ = 7863720.

The previous prime is 11817983. The next prime is 11817997. The reversal of 11817987 is 78971811.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 11817987 - 2² = 11817983 is a prime.

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 7 ways as a sum of consecutive naturals, for example, 1737 + ... + 5162.

It is an arithmetic number, because the mean of its divisors is an integer number (1973400).

Almost surely, 2^11817987 is an apocalyptic number.

11817987 is a deficient number, since it is larger than the sum of its proper divisors (3969213).

11817987 is an equidigital number, since it uses as much as digits as its factorization.

11817987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7473.

The product of its digits is 28224, while the sum is 42.

The square root of 11817987 is about 3437.7299195836. The cubic root of 11817987 is about 227.7794304240.

The spelling of 11817987 in words is "eleven million, eight hundred seventeen thousand, nine hundred eighty-seven".