221820182231 has 2 divisors, whose sum is σ = 221820182232. Its totient is φ = 221820182230.

The previous prime is 221820182203. The next prime is 221820182239. The reversal of 221820182231 is 132281028122.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221820182231 is a prime.

It is a super-2 number, since 2×221820182231² (a number of 23 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221820182239) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110910091115 + 110910091116.

It is an arithmetic number, because the mean of its divisors is an integer number (110910091116).

Almost surely, 2^221820182231 is an apocalyptic number.

221820182231 is a deficient number, since it is larger than the sum of its proper divisors (1).

221820182231 is an equidigital number, since it uses as much as digits as its factorization.

221820182231 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6144, while the sum is 32.

The spelling of 221820182231 in words is "two hundred twenty-one billion, eight hundred twenty million, one hundred eighty-two thousand, two hundred thirty-one".