221091839569 has 2 divisors, whose sum is σ = 221091839570. Its totient is φ = 221091839568.

The previous prime is 221091839561. The next prime is 221091839659. The reversal of 221091839569 is 965938190122.

Together with next prime (221091839659) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 153595799569 + 67496040000 = 391913^2 + 259800^2 .

It is a cyclic number.

It is not a de Polignac number, because 221091839569 - 2³ = 221091839561 is a prime.

It is a super-2 number, since 2×221091839569² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (221091839561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110545919784 + 110545919785.

It is an arithmetic number, because the mean of its divisors is an integer number (110545919785).

Almost surely, 2^221091839569 is an apocalyptic number.

It is an amenable number.

221091839569 is a deficient number, since it is larger than the sum of its proper divisors (1).

221091839569 is an equidigital number, since it uses as much as digits as its factorization.

221091839569 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2099520, while the sum is 55.

The spelling of 221091839569 in words is "two hundred twenty-one billion, ninety-one million, eight hundred thirty-nine thousand, five hundred sixty-nine".