221268791 has 2 divisors, whose sum is σ = 221268792. Its totient is φ = 221268790.

The previous prime is 221268779. The next prime is 221268797. The reversal of 221268791 is 197862122.

221268791 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 221268791 - 2⁶ = 221268727 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221268797) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110634395 + 110634396.

It is an arithmetic number, because the mean of its divisors is an integer number (110634396).

Almost surely, 2^221268791 is an apocalyptic number.

221268791 is a deficient number, since it is larger than the sum of its proper divisors (1).

221268791 is an equidigital number, since it uses as much as digits as its factorization.

221268791 is an evil number, because the sum of its binary digits is even.

The product of its digits is 24192, while the sum is 38.

The square root of 221268791 is about 14875.1064197874. The cubic root of 221268791 is about 604.8393726978.

The spelling of 221268791 in words is "two hundred twenty-one million, two hundred sixty-eight thousand, seven hundred ninety-one".