66836720 has 20 divisors (see below), whose sum is σ = 155395560. Its totient is φ = 26734656.

The previous prime is 66836701. The next prime is 66836807. The reversal of 66836720 is 2763866.

It is a tau number, because it is divible by the number of its divisors (20).

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 3 ways as a sum of consecutive naturals, for example, 417650 + ... + 417809.

It is an arithmetic number, because the mean of its divisors is an integer number (7769778).

Almost surely, 2^66836720 is an apocalyptic number.

It is an amenable number.

66836720 is an abundant number, since it is smaller than the sum of its proper divisors (88558840).

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

66836720 is a wasteful number, since it uses less digits than its factorization.

66836720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 835472 (or 835466 counting only the distinct ones).

The product of its (nonzero) digits is 72576, while the sum is 38.

The square root of 66836720 is about 8175.3727743755. The cubic root of 66836720 is about 405.8246065508.

The spelling of 66836720 in words is "sixty-six million, eight hundred thirty-six thousand, seven hundred twenty".