66339729225 has 243 divisors, whose sum is σ = 152613558279. Its totient is φ = 27446126400.

The previous prime is 66339729179. The next prime is 66339729299. The reversal of 66339729225 is 52292793366.

It is a happy number.

The square root of 66339729225 is 257565.

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

66339729225 is a `hidden beast` number, since 6 + 6 + 3 + 397 + 29 + 225 = 666.

It can be written as a sum of positive squares in only one way, i.e., 23882302521 + 42457426704 = 154539^2 + 206052^2 .

It is not a de Polignac number, because 66339729225 - 2¹³ = 66339721033 is a prime.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 242 ways as a sum of consecutive naturals, for example, 297487464 + ... + 297487686.

Almost surely, 2^66339729225 is an apocalyptic number.

66339729225 is the 257565-th square number.

66339729225 is the 128783-rd centered octagonal number.

It is an amenable number.

66339729225 is an abundant number, since it is smaller than the sum of its proper divisors (86273829054).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66339729225 is a wasteful number, since it uses less digits than its factorization.

66339729225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 498 (or 249 counting only the distinct ones).

The product of its digits is 7348320, while the sum is 54.

The spelling of 66339729225 in words is "sixty-six billion, three hundred thirty-nine million, seven hundred twenty-nine thousand, two hundred twenty-five".