221321191 has 12 divisors (see below), whose sum is σ = 277260312. Its totient is φ = 175110768.

The previous prime is 221321159. The next prime is 221321209. The reversal of 221321191 is 191123122.

It is not a de Polignac number, because 221321191 - 2⁵ = 221321159 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221321131) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 173085 + ... + 174358.

It is an arithmetic number, because the mean of its divisors is an integer number (23105026).

Almost surely, 2^221321191 is an apocalyptic number.

221321191 is a deficient number, since it is larger than the sum of its proper divisors (55939121).

221321191 is a wasteful number, since it uses less digits than its factorization.

221321191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 347470 (or 347463 counting only the distinct ones).

The product of its digits is 216, while the sum is 22.

The square root of 221321191 is about 14876.8676474586. The cubic root of 221321191 is about 604.8871141520.

The spelling of 221321191 in words is "two hundred twenty-one million, three hundred twenty-one thousand, one hundred ninety-one".