66499574400 has 1152 divisors, whose sum is σ = 296489356800. Its totient is φ = 14377512960.

The previous prime is 66499574371. The next prime is 66499574423. The reversal of 66499574400 is 447599466.

It is a happy number.

66499574400 is a `hidden beast` number, since 6 + 64 + 9 + 9 + 574 + 4 + 0 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (1152).

It is a super-2 number, since 2×66499574400² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 103420479 + ... + 103421121.

Almost surely, 2^66499574400 is an apocalyptic number.

66499574400 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 66499574400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (148244678400).

66499574400 is an abundant number, since it is smaller than the sum of its proper divisors (229989782400).

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

66499574400 is a wasteful number, since it uses less digits than its factorization.

66499574400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 708 (or 679 counting only the distinct ones).

The product of its (nonzero) digits is 6531840, while the sum is 54.

The spelling of 66499574400 in words is "sixty-six billion, four hundred ninety-nine million, five hundred seventy-four thousand, four hundred".