66904995600 has 315 divisors, whose sum is σ = 241502810533. Its totient is φ = 17804085120.

The previous prime is 66904995593. The next prime is 66904995607. The reversal of 66904995600 is 659940966.

It is a happy number.

The square root of 66904995600 is 258660.

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

66904995600 is a `hidden beast` number, since 6 + 6 + 90 + 499 + 5 + 60 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (66904995593) and next prime (66904995607).

It can be written as a sum of positive squares in only one way, i.e., 24085798416 + 42819197184 = 155196^2 + 206928^2 .

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66904995607) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 62 ways as a sum of consecutive naturals, for example, 139676161 + ... + 139676639.

Almost surely, 2^66904995600 is an apocalyptic number.

66904995600 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

66904995600 is the 258660-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66904995600

66904995600 is an abundant number, since it is smaller than the sum of its proper divisors (174597814933).

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

66904995600 is an frugal number, since it uses more digits than its factorization.

66904995600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 994 (or 489 counting only the distinct ones).

The product of its (nonzero) digits is 3149280, while the sum is 54.

The spelling of 66904995600 in words is "sixty-six billion, nine hundred four million, nine hundred ninety-five thousand, six hundred".