221090869 has 2 divisors, whose sum is σ = 221090870. Its totient is φ = 221090868.

The previous prime is 221090843. The next prime is 221090887. The reversal of 221090869 is 968090122.

221090869 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 171950769 + 49140100 = 13113^2 + 7010^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221090869 is a prime.

It is a super-3 number, since 3×221090869³ (a number of 26 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221099869) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110545434 + 110545435.

It is an arithmetic number, because the mean of its divisors is an integer number (110545435).

Almost surely, 2^221090869 is an apocalyptic number.

It is an amenable number.

221090869 is a deficient number, since it is larger than the sum of its proper divisors (1).

221090869 is an equidigital number, since it uses as much as digits as its factorization.

221090869 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 15552, while the sum is 37.

The square root of 221090869 is about 14869.1246884274. The cubic root of 221090869 is about 604.6772123264.

The spelling of 221090869 in words is "two hundred twenty-one million, ninety thousand, eight hundred sixty-nine".