66151720 has 32 divisors (see below), whose sum is σ = 149234400. Its totient is φ = 26390848.

The previous prime is 66151681. The next prime is 66151721. The reversal of 66151720 is 2715166.

66151720 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (66151721) 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 7 ways as a sum of consecutive naturals, for example, 14787 + ... + 18733.

It is an arithmetic number, because the mean of its divisors is an integer number (4663575).

Almost surely, 2^66151720 is an apocalyptic number.

It is an amenable number.

66151720 is an abundant number, since it is smaller than the sum of its proper divisors (83082680).

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

66151720 is a wasteful number, since it uses less digits than its factorization.

66151720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4377 (or 4373 counting only the distinct ones).

The product of its (nonzero) digits is 2520, while the sum is 28.

The square root of 66151720 is about 8133.3707649412. The cubic root of 66151720 is about 404.4334301991.

Adding to 66151720 its reverse (2715166), we get a palindrome (68866886).

The spelling of 66151720 in words is "sixty-six million, one hundred fifty-one thousand, seven hundred twenty".