66451266 has 112 divisors (see below), whose sum is σ = 181315584. Its totient is φ = 17822592.

The previous prime is 66451261. The next prime is 66451277. The reversal of 66451266 is 66215466.

It is a happy number.

66451266 is a `hidden beast` number, since 6 + 645 + 1 + 2 + 6 + 6 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 66451266.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66451261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 55 ways as a sum of consecutive naturals, for example, 173311 + ... + 173693.

Almost surely, 2^66451266 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66451266, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (90657792).

66451266 is an abundant number, since it is smaller than the sum of its proper divisors (114864318).

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

66451266 is a wasteful number, since it uses less digits than its factorization.

66451266 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 427 (or 412 counting only the distinct ones).

The product of its digits is 51840, while the sum is 36.

The square root of 66451266 is about 8151.7645942458. The cubic root of 66451266 is about 405.0429584062.

The spelling of 66451266 in words is "sixty-six million, four hundred fifty-one thousand, two hundred sixty-six".