11997155 has 32 divisors (see below), whose sum is σ = 16381440. Its totient is φ = 8386560.

The previous prime is 11997137. The next prime is 11997157. The reversal of 11997155 is 55179911.

It is a de Polignac number, because none of the positive numbers 2^k-11997155 is a prime.

It is not an unprimeable number, because it can be changed into a prime (11997157) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 76337 + ... + 76493.

It is an arithmetic number, because the mean of its divisors is an integer number (511920).

Almost surely, 2^11997155 is an apocalyptic number.

11997155 is a deficient number, since it is larger than the sum of its proper divisors (4384285).

11997155 is a wasteful number, since it uses less digits than its factorization.

11997155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 239.

The product of its digits is 14175, while the sum is 38.

The square root of 11997155 is about 3463.6909504169. The cubic root of 11997155 is about 228.9247542361.

The spelling of 11997155 in words is "eleven million, nine hundred ninety-seven thousand, one hundred fifty-five".