66704720 has 40 divisors (see below), whose sum is σ = 157642440. Its totient is φ = 26242560.

The previous prime is 66704689. The next prime is 66704749. The reversal of 66704720 is 2740766.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 1547536 + 65157184 = 1244^2 + 8072^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1955 + ... + 11714.

It is an arithmetic number, because the mean of its divisors is an integer number (3941061).

Almost surely, 2^66704720 is an apocalyptic number.

It is an amenable number.

66704720 is an abundant number, since it is smaller than the sum of its proper divisors (90937720).

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

66704720 is a wasteful number, since it uses less digits than its factorization.

66704720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13743 (or 13737 counting only the distinct ones).

The product of its (nonzero) digits is 14112, while the sum is 32.

The square root of 66704720 is about 8167.2957580830. The cubic root of 66704720 is about 405.5572677172.

The spelling of 66704720 in words is "sixty-six million, seven hundred four thousand, seven hundred twenty".