11981599 has 8 divisors (see below), whose sum is σ = 14063648. Its totient is φ = 9992160.

The previous prime is 11981587. The next prime is 11981603. The reversal of 11981599 is 99518911.

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

It is a cyclic number.

It is not a de Polignac number, because 11981599 - 2⁹ = 11981087 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11981399) 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, 22872 + ... + 23389.

It is an arithmetic number, because the mean of its divisors is an integer number (1757956).

Almost surely, 2^11981599 is an apocalyptic number.

11981599 is a deficient number, since it is larger than the sum of its proper divisors (2082049).

11981599 is an equidigital number, since it uses as much as digits as its factorization.

11981599 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46305.

The product of its digits is 29160, while the sum is 43.

The square root of 11981599 is about 3461.4446406089. Note that the first 3 decimals coincide. The cubic root of 11981599 is about 228.8257670522.

It can be divided in two parts, 119 and 81599, that added together give a palindrome (81718).

The spelling of 11981599 in words is "eleven million, nine hundred eighty-one thousand, five hundred ninety-nine".