11991285 has 24 divisors (see below), whose sum is σ = 20866560. Its totient is φ = 6370272.

The previous prime is 11991271. The next prime is 11991313. The reversal of 11991285 is 58219911.

It is not a de Polignac number, because 11991285 - 2⁴ = 11991269 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 19452 + ... + 20058.

It is an arithmetic number, because the mean of its divisors is an integer number (869440).

Almost surely, 2^11991285 is an apocalyptic number.

11991285 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

11991285 is a deficient number, since it is larger than the sum of its proper divisors (8875275).

11991285 is a wasteful number, since it uses less digits than its factorization.

11991285 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1057 (or 1054 counting only the distinct ones).

The product of its digits is 6480, while the sum is 36.

The square root of 11991285 is about 3462.8434847680. The cubic root of 11991285 is about 228.8874118403.

The spelling of 11991285 in words is "eleven million, nine hundred ninety-one thousand, two hundred eighty-five".