17281994521 has 81 divisors (see below), whose sum is σ = 21888151677. Its totient is φ = 13629876480.

The previous prime is 17281994503. The next prime is 17281994551. The reversal of 17281994521 is 12549918271.

The square root of 17281994521 is 131461.

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

It can be written as a sum of positive squares in 4 ways, for example, as 8039094921 + 9242899600 = 89661^2 + 96140^2 .

It is not a de Polignac number, because 17281994521 - 2⁵ = 17281994489 is a prime.

Its product of digits (362880) is a multiple of the sum of its prime divisors (84).

It is not an unprimeable number, because it can be changed into a prime (17281994551) by changing a digit.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 467080915 + ... + 467080951.

Almost surely, 2^17281994521 is an apocalyptic number.

17281994521 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

17281994521 is the 131461-st square number.

17281994521 is the 65731-st centered octagonal number.

It is an amenable number.

17281994521 is a deficient number, since it is larger than the sum of its proper divisors (4606157156).

17281994521 is a wasteful number, since it uses less digits than its factorization.

17281994521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 168 (or 84 counting only the distinct ones).

The product of its digits is 362880, while the sum is 49.

Multiplying 17281994521 by its sum of digits (49), we get a square (846817731529 = 920227²).

The spelling of 17281994521 in words is "seventeen billion, two hundred eighty-one million, nine hundred ninety-four thousand, five hundred twenty-one".