12912991 has 16 divisors (see below), whose sum is σ = 16285248. Its totient is φ = 9964800.

The previous prime is 12912971. The next prime is 12913003. The reversal of 12912991 is 19921921.

12912991 is digitally balanced in base 2 and base 8, because in such bases it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 12912991 - 2⁷ = 12912863 is a prime.

12912991 is strictly pandigital in base 8.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12912901) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2001 + ... + 5461.

It is an arithmetic number, because the mean of its divisors is an integer number (1017828).

Almost surely, 2^12912991 is an apocalyptic number.

12912991 is a deficient number, since it is larger than the sum of its proper divisors (3372257).

12912991 is a wasteful number, since it uses less digits than its factorization.

12912991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3522.

The product of its digits is 2916, while the sum is 34.

The square root of 12912991 is about 3593.4650408763. The cubic root of 12912991 is about 234.6077112878.

The spelling of 12912991 in words is "twelve million, nine hundred twelve thousand, nine hundred ninety-one".