66111920 has 40 divisors (see below), whose sum is σ = 175670304. Its totient is φ = 22666752.

The previous prime is 66111911. The next prime is 66111923. The reversal of 66111920 is 2911166.

66111920 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a self number, because there is not a number n which added to its sum of digits gives 66111920.

It is not an unprimeable number, because it can be changed into a prime (66111923) 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, 58469 + ... + 59588.

Almost surely, 2^66111920 is an apocalyptic number.

It is an amenable number.

66111920 is an abundant number, since it is smaller than the sum of its proper divisors (109558384).

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

66111920 is a wasteful number, since it uses less digits than its factorization.

66111920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 118077 (or 118071 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 26.

The square root of 66111920 is about 8130.9236867652. The cubic root of 66111920 is about 404.3523051746.

The spelling of 66111920 in words is "sixty-six million, one hundred eleven thousand, nine hundred twenty".