12801991 has 8 divisors (see below), whose sum is σ = 13731120. Its totient is φ = 11898432.

The previous prime is 12801989. The next prime is 12802033. The reversal of 12801991 is 19910821.

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 12801991 - 2¹ = 12801989 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 (12801911) 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, 5350 + ... + 7363.

It is an arithmetic number, because the mean of its divisors is an integer number (1716390).

Almost surely, 2^12801991 is an apocalyptic number.

12801991 is a deficient number, since it is larger than the sum of its proper divisors (929129).

12801991 is a wasteful number, since it uses less digits than its factorization.

12801991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12785.

The product of its (nonzero) digits is 1296, while the sum is 31.

The square root of 12801991 is about 3577.9870038892. The cubic root of 12801991 is about 233.9335470101.

The spelling of 12801991 in words is "twelve million, eight hundred one thousand, nine hundred ninety-one".