221977664729 has 2 divisors, whose sum is σ = 221977664730. Its totient is φ = 221977664728.

The previous prime is 221977664723. The next prime is 221977664743. The reversal of 221977664729 is 927466779122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 120372914704 + 101604750025 = 346948^2 + 318755^2 .

It is a cyclic number.

It is not a de Polignac number, because 221977664729 - 2²⁴ = 221960887513 is a prime.

It is not a weakly prime, because it can be changed into another prime (221977664723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110988832364 + 110988832365.

It is an arithmetic number, because the mean of its divisors is an integer number (110988832365).

Almost surely, 2^221977664729 is an apocalyptic number.

It is an amenable number.

221977664729 is a deficient number, since it is larger than the sum of its proper divisors (1).

221977664729 is an equidigital number, since it uses as much as digits as its factorization.

221977664729 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 32006016, while the sum is 62.

The spelling of 221977664729 in words is "two hundred twenty-one billion, nine hundred seventy-seven million, six hundred sixty-four thousand, seven hundred twenty-nine".