21203179166623 has 2 divisors, whose sum is σ = 21203179166624. Its totient is φ = 21203179166622.

The previous prime is 21203179166501. The next prime is 21203179166677. The reversal of 21203179166623 is 32666197130212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21203179166623 - 2¹³ = 21203179158431 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21203179164623) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10601589583311 + 10601589583312.

It is an arithmetic number, because the mean of its divisors is an integer number (10601589583312).

Almost surely, 2^{21203179166623} is an apocalyptic number.

21203179166623 is a deficient number, since it is larger than the sum of its proper divisors (1).

21203179166623 is an equidigital number, since it uses as much as digits as its factorization.

21203179166623 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 979776, while the sum is 49.

The spelling of 21203179166623 in words is "twenty-one trillion, two hundred three billion, one hundred seventy-nine million, one hundred sixty-six thousand, six hundred twenty-three".