221356879 has 2 divisors, whose sum is σ = 221356880. Its totient is φ = 221356878.

The previous prime is 221356823. The next prime is 221356901. The reversal of 221356879 is 978653122.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 221356879 - 2²³ = 212968271 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221356279) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110678439 + 110678440.

It is an arithmetic number, because the mean of its divisors is an integer number (110678440).

Almost surely, 2^221356879 is an apocalyptic number.

221356879 is a deficient number, since it is larger than the sum of its proper divisors (1).

221356879 is an equidigital number, since it uses as much as digits as its factorization.

221356879 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 181440, while the sum is 43.

The square root of 221356879 is about 14878.0670451507. The cubic root of 221356879 is about 604.9196250487.

The spelling of 221356879 in words is "two hundred twenty-one million, three hundred fifty-six thousand, eight hundred seventy-nine".