221535442409 has 2 divisors, whose sum is σ = 221535442410. Its totient is φ = 221535442408.

The previous prime is 221535442391. The next prime is 221535442417. The reversal of 221535442409 is 904244535122.

221535442409 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., 168161505625 + 53373936784 = 410075^2 + 231028^2 .

It is a cyclic number.

It is not a de Polignac number, because 221535442409 - 2²⁸ = 221267006953 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (221535445409) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110767721204 + 110767721205.

It is an arithmetic number, because the mean of its divisors is an integer number (110767721205).

Almost surely, 2^221535442409 is an apocalyptic number.

It is an amenable number.

221535442409 is a deficient number, since it is larger than the sum of its proper divisors (1).

221535442409 is an equidigital number, since it uses as much as digits as its factorization.

221535442409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 345600, while the sum is 41.

The spelling of 221535442409 in words is "two hundred twenty-one billion, five hundred thirty-five million, four hundred forty-two thousand, four hundred nine".