891156221 has 4 divisors (see below), whose sum is σ = 938059200. Its totient is φ = 844253244.

The previous prime is 891156157. The next prime is 891156251. The reversal of 891156221 is 122651198.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 891156221 - 2⁶ = 891156157 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 (891156251) 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, 23451461 + ... + 23451498.

It is an arithmetic number, because the mean of its divisors is an integer number (234514800).

Almost surely, 2^891156221 is an apocalyptic number.

It is an amenable number.

891156221 is a deficient number, since it is larger than the sum of its proper divisors (46902979).

891156221 is a wasteful number, since it uses less digits than its factorization.

891156221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46902978.

The product of its digits is 8640, while the sum is 35.

The square root of 891156221 is about 29852.2397987153. The cubic root of 891156221 is about 962.3165341209.

The spelling of 891156221 in words is "eight hundred ninety-one million, one hundred fifty-six thousand, two hundred twenty-one".