12023991 has 32 divisors (see below), whose sum is σ = 20574720. Its totient is φ = 6797952.

The previous prime is 12023971. The next prime is 12024007. The reversal of 12023991 is 19932021.

It is not a de Polignac number, because 12023991 - 2⁷ = 12023863 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12023971) 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, 21076 + ... + 21638.

It is an arithmetic number, because the mean of its divisors is an integer number (642960).

Almost surely, 2^12023991 is an apocalyptic number.

12023991 is a deficient number, since it is larger than the sum of its proper divisors (8550729).

12023991 is a wasteful number, since it uses less digits than its factorization.

12023991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 692 (or 686 counting only the distinct ones).

The product of its (nonzero) digits is 972, while the sum is 27.

The square root of 12023991 is about 3467.5626886907. The cubic root of 12023991 is about 229.0953182773.

The spelling of 12023991 in words is "twelve million, twenty-three thousand, nine hundred ninety-one".