666266400 has 432 divisors, whose sum is σ = 2512292328. Its totient is φ = 165888000.

The previous prime is 666266399. The next prime is 666266413. The reversal of 666266400 is 4662666.

666266400 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 12 ways, for example, as 7420176 + 658846224 = 2724^2 + 25668^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 10922370 + ... + 10922430.

Almost surely, 2^666266400 is an apocalyptic number.

666266400 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 666266400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1256146164).

666266400 is an abundant number, since it is smaller than the sum of its proper divisors (1846025928).

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

666266400 is a wasteful number, since it uses less digits than its factorization.

666266400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 165 (or 149 counting only the distinct ones).

The product of its (nonzero) digits is 62208, while the sum is 36.

The square root of 666266400 is about 25812.1366802518. The cubic root of 666266400 is about 873.4055971645.

It can be divided in two parts, 666266 and 400, that added together give a palindrome (666666).

The spelling of 666266400 in words is "six hundred sixty-six million, two hundred sixty-six thousand, four hundred".