221766565373 has 2 divisors, whose sum is σ = 221766565374. Its totient is φ = 221766565372.

The previous prime is 221766565313. The next prime is 221766565417. The reversal of 221766565373 is 373565667122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 182071183204 + 39695382169 = 426698^2 + 199237^2 .

It is a cyclic number.

It is not a de Polignac number, because 221766565373 - 2¹⁶ = 221766499837 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221766565313) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110883282686 + 110883282687.

It is an arithmetic number, because the mean of its divisors is an integer number (110883282687).

Almost surely, 2^221766565373 is an apocalyptic number.

It is an amenable number.

221766565373 is a deficient number, since it is larger than the sum of its proper divisors (1).

221766565373 is an equidigital number, since it uses as much as digits as its factorization.

221766565373 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9525600, while the sum is 53.

The spelling of 221766565373 in words is "two hundred twenty-one billion, seven hundred sixty-six million, five hundred sixty-five thousand, three hundred seventy-three".