66121057200 has 360 divisors, whose sum is σ = 237541671360. Its totient is φ = 15591859200.

The previous prime is 66121057193. The next prime is 66121057229. The reversal of 66121057200 is 275012166.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

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 71 ways as a sum of consecutive naturals, for example, 18068971 + ... + 18072629.

It is an arithmetic number, because the mean of its divisors is an integer number (659837976).

Almost surely, 2^66121057200 is an apocalyptic number.

66121057200 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 66121057200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (118770835680).

66121057200 is an abundant number, since it is smaller than the sum of its proper divisors (171420614160).

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

66121057200 is a wasteful number, since it uses less digits than its factorization.

66121057200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3765 (or 3717 counting only the distinct ones).

The product of its (nonzero) digits is 5040, while the sum is 30.

Adding to 66121057200 its reverse (275012166), we get a palindrome (66396069366).

The spelling of 66121057200 in words is "sixty-six billion, one hundred twenty-one million, fifty-seven thousand, two hundred".