66653720 has 96 divisors (see below), whose sum is σ = 180247680. Its totient is φ = 22095360.

The previous prime is 66653711. The next prime is 66653749. The reversal of 66653720 is 2735666.

66653720 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a hoax number, since the sum of its digits (35) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a congruent number.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 60212 + ... + 61308.

It is an arithmetic number, because the mean of its divisors is an integer number (1877580).

Almost surely, 2^66653720 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66653720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (90123840).

66653720 is an abundant number, since it is smaller than the sum of its proper divisors (113593960).

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

66653720 is a wasteful number, since it uses less digits than its factorization.

66653720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1153 (or 1142 counting only the distinct ones).

The product of its (nonzero) digits is 45360, while the sum is 35.

The square root of 66653720 is about 8164.1729526021. The cubic root of 66653720 is about 405.4538832583.

The spelling of 66653720 in words is "sixty-six million, six hundred fifty-three thousand, seven hundred twenty".