17666343828225 has 405 divisors, whose sum is σ = 35619825326547. Its totient is φ = 8655095592000.

The previous prime is 17666343828223. The next prime is 17666343828241. The reversal of 17666343828225 is 52282834366671.

The square root of 17666343828225 is 4203135.

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

It can be written as a sum of positive squares in only one way, i.e., 6359883778161 + 11306460050064 = 2521881^2 + 3362508^2 .

It is a tau number, because it is divible by the number of its divisors (405).

It is not a de Polignac number, because 17666343828225 - 2¹ = 17666343828223 is a prime.

It is not an unprimeable number, because it can be changed into a prime (17666343828223) by changing a digit.

It is a polite number, since it can be written in 404 ways as a sum of consecutive naturals, for example, 134857586410 + ... + 134857586540.

Almost surely, 2^{17666343828225} is an apocalyptic number.

17666343828225 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

17666343828225 is the 4203135-th square number.

17666343828225 is the 2101568-th centered octagonal number.

It is an amenable number.

17666343828225 is an abundant number, since it is smaller than the sum of its proper divisors (17953481498322).

17666343828225 is an equidigital number, since it uses as much as digits as its factorization.

17666343828225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 392 (or 193 counting only the distinct ones).

The product of its digits is 139345920, while the sum is 63.

The spelling of 17666343828225 in words is "seventeen trillion, six hundred sixty-six billion, three hundred forty-three million, eight hundred twenty-eight thousand, two hundred twenty-five".