221873879 has 2 divisors, whose sum is σ = 221873880. Its totient is φ = 221873878.

The previous prime is 221873843. The next prime is 221873891. The reversal of 221873879 is 978378122.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221873879 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221878879) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110936939 + 110936940.

It is an arithmetic number, because the mean of its divisors is an integer number (110936940).

Almost surely, 2^221873879 is an apocalyptic number.

221873879 is a deficient number, since it is larger than the sum of its proper divisors (1).

221873879 is an equidigital number, since it uses as much as digits as its factorization.

221873879 is an evil number, because the sum of its binary digits is even.

The product of its digits is 338688, while the sum is 47.

The square root of 221873879 is about 14895.4314808266. The cubic root of 221873879 is about 605.3902079408.

The spelling of 221873879 in words is "two hundred twenty-one million, eight hundred seventy-three thousand, eight hundred seventy-nine".