66983753520 has 400 divisors, whose sum is σ = 239032805088. Its totient is φ = 17378426880.

The previous prime is 66983753519. The next prime is 66983753527. The reversal of 66983753520 is 2535738966.

It is a happy number.

66983753520 is a `hidden beast` number, since 6 + 6 + 9 + 83 + 7 + 535 + 20 = 666.

It is a super-2 number, since 2×66983753520² (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 not an unprimeable number, because it can be changed into a prime (66983753527) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 38341287 + ... + 38343033.

Almost surely, 2^66983753520 is an apocalyptic number.

66983753520 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 66983753520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (119516402544).

66983753520 is an abundant number, since it is smaller than the sum of its proper divisors (172049051568).

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

66983753520 is a wasteful number, since it uses less digits than its factorization.

66983753520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1930 (or 1915 counting only the distinct ones).

The product of its (nonzero) digits is 8164800, while the sum is 54.

The spelling of 66983753520 in words is "sixty-six billion, nine hundred eighty-three million, seven hundred fifty-three thousand, five hundred twenty".