221081911091 has 2 divisors, whose sum is σ = 221081911092. Its totient is φ = 221081911090.

The previous prime is 221081911033. The next prime is 221081911129. The reversal of 221081911091 is 190119180122.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 221081911091 - 2¹⁴ = 221081894707 is a prime.

It is a super-2 number, since 2×221081911091² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (221081911031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110540955545 + 110540955546.

It is an arithmetic number, because the mean of its divisors is an integer number (110540955546).

Almost surely, 2^221081911091 is an apocalyptic number.

221081911091 is a deficient number, since it is larger than the sum of its proper divisors (1).

221081911091 is an equidigital number, since it uses as much as digits as its factorization.

221081911091 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2592, while the sum is 35.

The spelling of 221081911091 in words is "two hundred twenty-one billion, eighty-one million, nine hundred eleven thousand, ninety-one".