891344991 has 4 divisors (see below), whose sum is σ = 1188459992. Its totient is φ = 594229992.

The previous prime is 891344981. The next prime is 891345001. The reversal of 891344991 is 199443198.

891344991 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (891344981) and next prime (891345001).

It is not a de Polignac number, because 891344991 - 2⁹ = 891344479 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 891344991.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (891344941) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 148557496 + ... + 148557501.

It is an arithmetic number, because the mean of its divisors is an integer number (297114998).

Almost surely, 2^891344991 is an apocalyptic number.

891344991 is a deficient number, since it is larger than the sum of its proper divisors (297115001).

891344991 is a wasteful number, since it uses less digits than its factorization.

891344991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 297115000.

The product of its digits is 279936, while the sum is 48.

The square root of 891344991 is about 29855.4013706063. The cubic root of 891344991 is about 962.3844771903.

The spelling of 891344991 in words is "eight hundred ninety-one million, three hundred forty-four thousand, nine hundred ninety-one".