12651991 has 8 divisors (see below), whose sum is σ = 13847184. Its totient is φ = 11464320.

The previous prime is 12651983. The next prime is 12651997. The reversal of 12651991 is 19915621.

It is a happy number.

12651991 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 12651991 - 2³ = 12651983 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 (12651997) 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, 2001 + ... + 5413.

It is an arithmetic number, because the mean of its divisors is an integer number (1730898).

Almost surely, 2^12651991 is an apocalyptic number.

12651991 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

12651991 is a deficient number, since it is larger than the sum of its proper divisors (1195193).

12651991 is a wasteful number, since it uses less digits than its factorization.

12651991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3761.

The product of its digits is 4860, while the sum is 34.

The square root of 12651991 is about 3556.9637332984. The cubic root of 12651991 is about 233.0162943654.

The spelling of 12651991 in words is "twelve million, six hundred fifty-one thousand, nine hundred ninety-one".