891000169 has 2 divisors, whose sum is σ = 891000170. Its totient is φ = 891000168.

The previous prime is 891000163. The next prime is 891000203. The reversal of 891000169 is 961000198.

It is an a-pointer prime, because the next prime (891000203) can be obtained adding 891000169 to its sum of digits (34).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 816816400 + 74183769 = 28580^2 + 8613^2 .

It is a cyclic number.

It is not a de Polignac number, because 891000169 - 2⁹ = 890999657 is a prime.

It is a super-2 number, since 2×891000169² = 1587762602316057122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (891000163) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 445500084 + 445500085.

It is an arithmetic number, because the mean of its divisors is an integer number (445500085).

Almost surely, 2^891000169 is an apocalyptic number.

It is an amenable number.

891000169 is a deficient number, since it is larger than the sum of its proper divisors (1).

891000169 is an equidigital number, since it uses as much as digits as its factorization.

891000169 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3888, while the sum is 34.

The square root of 891000169 is about 29849.6259440550. The cubic root of 891000169 is about 962.2603598375.

The spelling of 891000169 in words is "eight hundred ninety-one million, one hundred sixty-nine", and thus it is an aban number.