66836689920 has 2640 divisors, whose sum is σ = 341546502528. Its totient is φ = 12262440960.

The previous prime is 66836689919. The next prime is 66836689991. The reversal of 66836689920 is 2998663866.

66836689920 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (2640).

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 polite number, since it can be written in 239 ways as a sum of consecutive naturals, for example, 2905943029 + ... + 2905943051.

Almost surely, 2^66836689920 is an apocalyptic number.

66836689920 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 66836689920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (170773251264).

66836689920 is an abundant number, since it is smaller than the sum of its proper divisors (274709812608).

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

66836689920 is a wasteful number, since it uses less digits than its factorization.

66836689920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 98 (or 64 counting only the distinct ones).

The product of its (nonzero) digits is 40310784, while the sum is 63.

The spelling of 66836689920 in words is "sixty-six billion, eight hundred thirty-six million, six hundred eighty-nine thousand, nine hundred twenty".