66481905600 has 672 divisors, whose sum is σ = 272972052480. Its totient is φ = 15593472000.

The previous prime is 66481905577. The next prime is 66481905619. The reversal of 66481905600 is 650918466.

66481905600 is a `hidden beast` number, since 6 + 6 + 4 + 81 + 9 + 0 + 560 + 0 = 666.

It is a super-2 number, since 2×66481905600² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

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, 14728944 + ... + 14733456.

Almost surely, 2^66481905600 is an apocalyptic number.

66481905600 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 66481905600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (136486026240).

66481905600 is an abundant number, since it is smaller than the sum of its proper divisors (206490146880).

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

66481905600 is a wasteful number, since it uses less digits than its factorization.

66481905600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4586 (or 4565 counting only the distinct ones).

The product of its (nonzero) digits is 311040, while the sum is 45.

The spelling of 66481905600 in words is "sixty-six billion, four hundred eighty-one million, nine hundred five thousand, six hundred".