66001600 has 168 divisors, whose sum is σ = 190487808. Its totient is φ = 22041600.

The previous prime is 66001597. The next prime is 66001609. The reversal of 66001600 is 610066.

It is a happy number.

It is a super-2 number, since 2×66001600² = 8712422405120000, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (66001609) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 795159 + ... + 795241.

It is an arithmetic number, because the mean of its divisors is an integer number (1133856).

Almost surely, 2^66001600 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 66001600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (95243904).

66001600 is an abundant number, since it is smaller than the sum of its proper divisors (124486208).

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

66001600 is a wasteful number, since it uses less digits than its factorization.

66001600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 183 (or 168 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 19.

The square root of 66001600 is about 8124.1368772319. The cubic root of 66001600 is about 404.1272676843.

Adding to 66001600 its reverse (610066), we get a palindrome (66611666).

The spelling of 66001600 in words is "sixty-six million, one thousand, six hundred".