221385869 has 2 divisors, whose sum is σ = 221385870. Its totient is φ = 221385868.

The previous prime is 221385847. The next prime is 221385907. The reversal of 221385869 is 968583122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 151044100 + 70341769 = 12290^2 + 8387^2 .

It is a cyclic number.

It is not a de Polignac number, because 221385869 - 2⁸ = 221385613 is a prime.

It is a super-2 number, since 2×221385869² = 98023405985770322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221325869) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110692934 + 110692935.

It is an arithmetic number, because the mean of its divisors is an integer number (110692935).

Almost surely, 2^221385869 is an apocalyptic number.

It is an amenable number.

221385869 is a deficient number, since it is larger than the sum of its proper divisors (1).

221385869 is an equidigital number, since it uses as much as digits as its factorization.

221385869 is an evil number, because the sum of its binary digits is even.

The product of its digits is 207360, while the sum is 44.

The square root of 221385869 is about 14879.0412661569. The cubic root of 221385869 is about 604.9460316589.

The spelling of 221385869 in words is "two hundred twenty-one million, three hundred eighty-five thousand, eight hundred sixty-nine".