222686521 has 2 divisors, whose sum is σ = 222686522. Its totient is φ = 222686520.

The previous prime is 222686491. The next prime is 222686533. The reversal of 222686521 is 125686222.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 206324496 + 16362025 = 14364^2 + 4045^2 .

It is a cyclic number.

It is not a de Polignac number, because 222686521 - 2¹⁹ = 222162233 is a prime.

It is not a weakly prime, because it can be changed into another prime (222684521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 111343260 + 111343261.

It is an arithmetic number, because the mean of its divisors is an integer number (111343261).

Almost surely, 2^222686521 is an apocalyptic number.

It is an amenable number.

222686521 is a deficient number, since it is larger than the sum of its proper divisors (1).

222686521 is an equidigital number, since it uses as much as digits as its factorization.

222686521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 23040, while the sum is 34.

The square root of 222686521 is about 14922.6847785511. The cubic root of 222686521 is about 606.1284142610.

The spelling of 222686521 in words is "two hundred twenty-two million, six hundred eighty-six thousand, five hundred twenty-one".