220391 has 2 divisors, whose sum is σ = 220392. Its totient is φ = 220390.

The previous prime is 220373. The next prime is 220399. The reversal of 220391 is 193022.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 220391 - 2⁶ = 220327 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 (220399) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110195 + 110196.

It is an arithmetic number, because the mean of its divisors is an integer number (110196).

2²²⁰³⁹¹ is an apocalyptic number.

220391 is a deficient number, since it is larger than the sum of its proper divisors (1).

220391 is an equidigital number, since it uses as much as digits as its factorization.

220391 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 108, while the sum is 17.

The square root of 220391 is about 469.4581983521. The cubic root of 220391 is about 60.4038497320.

The spelling of 220391 in words is "two hundred twenty thousand, three hundred ninety-one".