66958597440 has 336 divisors, whose sum is σ = 264989462400. Its totient is φ = 15201423360.

The previous prime is 66958597421. The next prime is 66958597523. The reversal of 66958597440 is 4479585966.

66958597440 is a `hidden beast` number, since 6 + 6 + 9 + 585 + 9 + 7 + 4 + 40 = 666.

It is a tau number, because it is divible by the number of its divisors (336).

It is a super-2 number, since 2×66958597440² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2992695 + ... + 3014985.

Almost surely, 2^66958597440 is an apocalyptic number.

66958597440 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 66958597440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (132494731200).

66958597440 is an abundant number, since it is smaller than the sum of its proper divisors (198030864960).

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

66958597440 is a wasteful number, since it uses less digits than its factorization.

66958597440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22470 (or 22457 counting only the distinct ones).

The product of its (nonzero) digits is 65318400, while the sum is 63.

The spelling of 66958597440 in words is "sixty-six billion, nine hundred fifty-eight million, five hundred ninety-seven thousand, four hundred forty".