66662500 has 36 divisors (see below), whose sum is σ = 145842228. Its totient is φ = 26660000.

The previous prime is 66662489. The next prime is 66662509. The reversal of 66662500 is 526666.

66662500 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 6 ways, for example, as 32626944 + 34035556 = 5712^2 + 5834^2 .

It is a super-4 number, since 4×66662500⁴ (a number of 32 digits) contains 4444 as substring.

It is not an unprimeable number, because it can be changed into a prime (66662509) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9834 + ... + 15166.

It is an arithmetic number, because the mean of its divisors is an integer number (4051173).

Almost surely, 2^66662500 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66662500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (72921114).

66662500 is an abundant number, since it is smaller than the sum of its proper divisors (79179728).

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

66662500 is an equidigital number, since it uses as much as digits as its factorization.

66662500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5362 (or 5340 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 31.

The square root of 66662500 is about 8164.7106501088. The cubic root of 66662500 is about 405.4716853595.

The spelling of 66662500 in words is "sixty-six million, six hundred sixty-two thousand, five hundred".