891911749 has 4 divisors (see below), whose sum is σ = 944377164. Its totient is φ = 839446336.

The previous prime is 891911743. The next prime is 891911753. The reversal of 891911749 is 947119198.

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

It can be written as a sum of positive squares in 2 ways, for example, as 717275524 + 174636225 = 26782^2 + 13215^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-891911749 is a prime.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (891911743) 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, 26232682 + ... + 26232715.

It is an arithmetic number, because the mean of its divisors is an integer number (236094291).

Almost surely, 2^891911749 is an apocalyptic number.

It is an amenable number.

891911749 is a deficient number, since it is larger than the sum of its proper divisors (52465415).

891911749 is a wasteful number, since it uses less digits than its factorization.

891911749 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52465414.

The product of its digits is 163296, while the sum is 49.

The square root of 891911749 is about 29864.8915785743. The cubic root of 891911749 is about 962.5884100270.

The spelling of 891911749 in words is "eight hundred ninety-one million, nine hundred eleven thousand, seven hundred forty-nine".