66625720 has 64 divisors (see below), whose sum is σ = 181414080. Its totient is φ = 21497856.

The previous prime is 66625709. The next prime is 66625721. The reversal of 66625720 is 2752666.

It is a happy number.

66625720 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (34).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66625721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2239 + ... + 11758.

It is an arithmetic number, because the mean of its divisors is an integer number (2834595).

Almost surely, 2^66625720 is an apocalyptic number.

It is an amenable number.

66625720 is an abundant number, since it is smaller than the sum of its proper divisors (114788360).

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

66625720 is a wasteful number, since it uses less digits than its factorization.

66625720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14032 (or 14028 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 34.

The square root of 66625720 is about 8162.4579631383. The cubic root of 66625720 is about 405.3971007372.

The spelling of 66625720 in words is "sixty-six million, six hundred twenty-five thousand, seven hundred twenty".