6661008225 has 27 divisors (see below), whose sum is σ = 11932798969. Its totient is φ = 3551884800.

The previous prime is 6661008169. The next prime is 6661008227. The reversal of 6661008225 is 5228001666.

The square root of 6661008225 is 81615.

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 59120721 + 6601887504 = 7689^2 + 81252^2 .

It is not a de Polignac number, because 6661008225 - 2¹⁵ = 6660975457 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 6661008225.

It is not an unprimeable number, because it can be changed into a prime (6661008227) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 1221505 + ... + 1226945.

Almost surely, 2^6661008225 is an apocalyptic number.

6661008225 is the 81615-th square number.

6661008225 is the 40808-th centered octagonal number.

It is an amenable number.

6661008225 is a deficient number, since it is larger than the sum of its proper divisors (5271790744).

6661008225 is an frugal number, since it uses more digits than its factorization.

6661008225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10898 (or 5449 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 36.

The cubic root of 6661008225 is about 1881.5394272931.

Multiplying 6661008225 by its sum of digits (36), we get a square (239796296100 = 489690²).

The spelling of 6661008225 in words is "six billion, six hundred sixty-one million, eight thousand, two hundred twenty-five".