16661172206453 has 2 divisors, whose sum is σ = 16661172206454. Its totient is φ = 16661172206452.

The previous prime is 16661172206411. The next prime is 16661172206489. The reversal of 16661172206453 is 35460227116661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9604408413604 + 7056763792849 = 3099098^2 + 2656457^2 .

It is a cyclic number.

It is not a de Polignac number, because 16661172206453 - 2⁸ = 16661172206197 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16661172208453) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8330586103226 + 8330586103227.

It is an arithmetic number, because the mean of its divisors is an integer number (8330586103227).

Almost surely, 2^{16661172206453} is an apocalyptic number.

It is an amenable number.

16661172206453 is a deficient number, since it is larger than the sum of its proper divisors (1).

16661172206453 is an equidigital number, since it uses as much as digits as its factorization.

16661172206453 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2177280, while the sum is 50.

The spelling of 16661172206453 in words is "sixteen trillion, six hundred sixty-one billion, one hundred seventy-two million, two hundred six thousand, four hundred fifty-three".