221881969 has 2 divisors, whose sum is σ = 221881970. Its totient is φ = 221881968.

The previous prime is 221881963. The next prime is 221882027. The reversal of 221881969 is 969188122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 220225600 + 1656369 = 14840^2 + 1287^2 .

It is a cyclic number.

It is not a de Polignac number, because 221881969 - 2⁵ = 221881937 is a prime.

It is a super-2 number, since 2×221881969² = 98463216334633922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (221881963) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110940984 + 110940985.

It is an arithmetic number, because the mean of its divisors is an integer number (110940985).

Almost surely, 2^221881969 is an apocalyptic number.

It is an amenable number.

221881969 is a deficient number, since it is larger than the sum of its proper divisors (1).

221881969 is an equidigital number, since it uses as much as digits as its factorization.

221881969 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 124416, while the sum is 46.

The square root of 221881969 is about 14895.7030381248. The cubic root of 221881969 is about 605.3975657955.

The spelling of 221881969 in words is "two hundred twenty-one million, eight hundred eighty-one thousand, nine hundred sixty-nine".