221335123409 has 2 divisors, whose sum is σ = 221335123410. Its totient is φ = 221335123408.

The previous prime is 221335123349. The next prime is 221335123447. The reversal of 221335123409 is 904321533122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 207414663184 + 13920460225 = 455428^2 + 117985^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221335123409 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 (221335123309) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110667561704 + 110667561705.

It is an arithmetic number, because the mean of its divisors is an integer number (110667561705).

Almost surely, 2^221335123409 is an apocalyptic number.

It is an amenable number.

221335123409 is a deficient number, since it is larger than the sum of its proper divisors (1).

221335123409 is an equidigital number, since it uses as much as digits as its factorization.

221335123409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 38880, while the sum is 35.

The spelling of 221335123409 in words is "two hundred twenty-one billion, three hundred thirty-five million, one hundred twenty-three thousand, four hundred nine".