66915342400 has 189 divisors, whose sum is σ = 171295181031. Its totient is φ = 25727278080.

The previous prime is 66915342397. The next prime is 66915342409. The reversal of 66915342400 is 424351966.

The square root of 66915342400 is 258680.

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

It can be written as a sum of positive squares in 4 ways, for example, as 919787584 + 65995554816 = 30328^2 + 256896^2 .

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66915342409) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 300068689 + ... + 300068911.

Almost surely, 2^66915342400 is an apocalyptic number.

66915342400 is the 258680-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66915342400

66915342400 is an abundant number, since it is smaller than the sum of its proper divisors (104379838631).

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

66915342400 is an equidigital number, since it uses as much as digits as its factorization.

66915342400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 526 (or 259 counting only the distinct ones).

The product of its (nonzero) digits is 155520, while the sum is 40.

The spelling of 66915342400 in words is "sixty-six billion, nine hundred fifteen million, three hundred forty-two thousand, four hundred".