66361720 has 32 divisors (see below), whose sum is σ = 153352800. Its totient is φ = 25826688.

The previous prime is 66361709. The next prime is 66361723. The reversal of 66361720 is 2716366.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66361723) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20940 + ... + 23899.

It is an arithmetic number, because the mean of its divisors is an integer number (4792275).

Almost surely, 2^66361720 is an apocalyptic number.

It is an amenable number.

66361720 is an abundant number, since it is smaller than the sum of its proper divisors (86991080).

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

66361720 is a wasteful number, since it uses less digits than its factorization.

66361720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44887 (or 44883 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 31.

The square root of 66361720 is about 8146.2703122349. The cubic root of 66361720 is about 404.8609388956.

It can be divided in two parts, 66361 and 720, that added together give a square (67081 = 259²).

The spelling of 66361720 in words is "sixty-six million, three hundred sixty-one thousand, seven hundred twenty".