221660539 has 2 divisors, whose sum is σ = 221660540. Its totient is φ = 221660538.

The previous prime is 221660513. The next prime is 221660557. The reversal of 221660539 is 935066122.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 221660539 - 2²³ = 213271931 is a prime.

It is not a weakly prime, because it can be changed into another prime (221660639) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110830269 + 110830270.

It is an arithmetic number, because the mean of its divisors is an integer number (110830270).

Almost surely, 2^221660539 is an apocalyptic number.

221660539 is a deficient number, since it is larger than the sum of its proper divisors (1).

221660539 is an equidigital number, since it uses as much as digits as its factorization.

221660539 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 19440, while the sum is 34.

The square root of 221660539 is about 14888.2685024149. The cubic root of 221660539 is about 605.1961106379.

The spelling of 221660539 in words is "two hundred twenty-one million, six hundred sixty thousand, five hundred thirty-nine".