66587961600 has 270 divisors, whose sum is σ = 246207950450. Its totient is φ = 17756651520.

The previous prime is 66587961593. The next prime is 66587961617. The reversal of 66587961600 is 616978566.

It can be written as a sum of positive squares in 3 ways, for example, as 4311760896 + 62276200704 = 65664^2 + 249552^2 .

It is a tau number, because it is divible by the number of its divisors (270).

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 29 ways as a sum of consecutive naturals, for example, 454176 + ... + 582624.

Almost surely, 2^66587961600 is an apocalyptic number.

66587961600 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 66587961600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (123103975225).

66587961600 is an abundant number, since it is smaller than the sum of its proper divisors (179619988850).

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

66587961600 is a wasteful number, since it uses less digits than its factorization.

66587961600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 128487 (or 128459 counting only the distinct ones).

The product of its (nonzero) digits is 3265920, while the sum is 54.

The spelling of 66587961600 in words is "sixty-six billion, five hundred eighty-seven million, nine hundred sixty-one thousand, six hundred".