221809969187 has 2 divisors, whose sum is σ = 221809969188. Its totient is φ = 221809969186.

The previous prime is 221809969103. The next prime is 221809969193. The reversal of 221809969187 is 781969908122.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 221809969187 - 2⁸ = 221809968931 is a prime.

It is not a weakly prime, because it can be changed into another prime (221809969387) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110904984593 + 110904984594.

It is an arithmetic number, because the mean of its divisors is an integer number (110904984594).

Almost surely, 2^221809969187 is an apocalyptic number.

221809969187 is a deficient number, since it is larger than the sum of its proper divisors (1).

221809969187 is an equidigital number, since it uses as much as digits as its factorization.

221809969187 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7838208, while the sum is 62.

The spelling of 221809969187 in words is "two hundred twenty-one billion, eight hundred nine million, nine hundred sixty-nine thousand, one hundred eighty-seven".