221323216129 has 2 divisors, whose sum is σ = 221323216130. Its totient is φ = 221323216128.

The previous prime is 221323216117. The next prime is 221323216133. The reversal of 221323216129 is 921612323122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 177558576129 + 43764640000 = 421377^2 + 209200^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221323216129 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 221323216094 and 221323216103.

It is not a weakly prime, because it can be changed into another prime (221323216139) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110661608064 + 110661608065.

It is an arithmetic number, because the mean of its divisors is an integer number (110661608065).

Almost surely, 2^221323216129 is an apocalyptic number.

It is an amenable number.

221323216129 is a deficient number, since it is larger than the sum of its proper divisors (1).

221323216129 is an equidigital number, since it uses as much as digits as its factorization.

221323216129 is an evil number, because the sum of its binary digits is even.

The product of its digits is 15552, while the sum is 34.

The spelling of 221323216129 in words is "two hundred twenty-one billion, three hundred twenty-three million, two hundred sixteen thousand, one hundred twenty-nine".