221689379 has 2 divisors, whose sum is σ = 221689380. Its totient is φ = 221689378.

The previous prime is 221689331. The next prime is 221689421. The reversal of 221689379 is 973986122.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 221689379 - 2¹² = 221685283 is a prime.

It is a super-2 number, since 2×221689379² = 98292361522811282, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (221689309) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110844689 + 110844690.

It is an arithmetic number, because the mean of its divisors is an integer number (110844690).

Almost surely, 2^221689379 is an apocalyptic number.

221689379 is a deficient number, since it is larger than the sum of its proper divisors (1).

221689379 is an equidigital number, since it uses as much as digits as its factorization.

221689379 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 326592, while the sum is 47.

The square root of 221689379 is about 14889.2370187327. The cubic root of 221689379 is about 605.2223566249. Note that the first 3 decimals are identical.

The spelling of 221689379 in words is "two hundred twenty-one million, six hundred eighty-nine thousand, three hundred seventy-nine".