221287384529 has 2 divisors, whose sum is σ = 221287384530. Its totient is φ = 221287384528.

The previous prime is 221287384453. The next prime is 221287384567. The reversal of 221287384529 is 925483782122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 212476746304 + 8810638225 = 460952^2 + 93865^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221287384529 is a prime.

It is not a weakly prime, because it can be changed into another prime (221287384429) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110643692264 + 110643692265.

It is an arithmetic number, because the mean of its divisors is an integer number (110643692265).

Almost surely, 2^221287384529 is an apocalyptic number.

It is an amenable number.

221287384529 is a deficient number, since it is larger than the sum of its proper divisors (1).

221287384529 is an equidigital number, since it uses as much as digits as its factorization.

221287384529 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3870720, while the sum is 53.

The spelling of 221287384529 in words is "two hundred twenty-one billion, two hundred eighty-seven million, three hundred eighty-four thousand, five hundred twenty-nine".