17966453521 has 3 divisors (see below), whose sum is σ = 17966587561. Its totient is φ = 17966319482.

The previous prime is 17966453501. The next prime is 17966453539. The reversal of 17966453521 is 12535466971.

The square root of 17966453521 is 134039.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 12535466971 = 24971 ⋅502001.

It is not a de Polignac number, because 17966453521 - 2⁵ = 17966453489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (17966453501) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 67020 + ... + 201058.

Almost surely, 2^17966453521 is an apocalyptic number.

17966453521 is the 134039-th square number.

17966453521 is the 67020-th centered octagonal number.

It is an amenable number.

17966453521 is a deficient number, since it is larger than the sum of its proper divisors (134040).

17966453521 is an frugal number, since it uses more digits than its factorization.

17966453521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 268078 (or 134039 counting only the distinct ones).

The product of its digits is 1360800, while the sum is 49.

Multiplying 17966453521 by its sum of digits (49), we get a square (880356222529 = 938273²).

The spelling of 17966453521 in words is "seventeen billion, nine hundred sixty-six million, four hundred fifty-three thousand, five hundred twenty-one".