66451432320 has 768 divisors, whose sum is σ = 294881428800. Its totient is φ = 14018199552.

The previous prime is 66451432303. The next prime is 66451432351. The reversal of 66451432320 is 2323415466.

66451432320 is a `hidden beast` number, since 6 + 645 + 1 + 4 + 3 + 2 + 3 + 2 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 11004342 + ... + 11010378.

Almost surely, 2^66451432320 is an apocalyptic number.

66451432320 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 66451432320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (147440714400).

66451432320 is an abundant number, since it is smaller than the sum of its proper divisors (228429996480).

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

66451432320 is a wasteful number, since it uses less digits than its factorization.

66451432320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6092 (or 6067 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 36.

Adding to 66451432320 its reverse (2323415466), we get a palindrome (68774847786).

The spelling of 66451432320 in words is "sixty-six billion, four hundred fifty-one million, four hundred thirty-two thousand, three hundred twenty".