66155020800 has 480 divisors, whose sum is σ = 250984293120. Its totient is φ = 15191654400.

The previous prime is 66155020793. The next prime is 66155020817. The reversal of 66155020800 is 802055166.

It is a tau number, because it is divible by the number of its divisors (480).

It is a Harshad number since it is a multiple of its sum of digits (33).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 8021479 + ... + 8029721.

It is an arithmetic number, because the mean of its divisors is an integer number (522883944).

Almost surely, 2^66155020800 is an apocalyptic number.

66155020800 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 66155020800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (125492146560).

66155020800 is an abundant number, since it is smaller than the sum of its proper divisors (184829272320).

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

66155020800 is a wasteful number, since it uses less digits than its factorization.

66155020800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8304 (or 8283 counting only the distinct ones).

The product of its (nonzero) digits is 14400, while the sum is 33.

Adding to 66155020800 its reverse (802055166), we get a palindrome (66957075966).

The spelling of 66155020800 in words is "sixty-six billion, one hundred fifty-five million, twenty thousand, eight hundred".