66604923840 has 336 divisors, whose sum is σ = 264921687072. Its totient is φ = 14052777984.

The previous prime is 66604923797. The next prime is 66604923851. The reversal of 66604923840 is 4832940666.

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

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a self number, because there is not a number n which added to its sum of digits gives 66604923840.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 557062 + ... + 665978.

It is an arithmetic number, because the mean of its divisors is an integer number (788457402).

Almost surely, 2^66604923840 is an apocalyptic number.

66604923840 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 66604923840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (132460843536).

66604923840 is an abundant number, since it is smaller than the sum of its proper divisors (198316763232).

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

66604923840 is a wasteful number, since it uses less digits than its factorization.

66604923840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 108964 (or 108947 counting only the distinct ones).

The product of its (nonzero) digits is 1492992, while the sum is 48.

The spelling of 66604923840 in words is "sixty-six billion, six hundred four million, nine hundred twenty-three thousand, eight hundred forty".