66071920 has 40 divisors (see below), whose sum is σ = 156525696. Its totient is φ = 25928448.

The previous prime is 66071857. The next prime is 66071921. The reversal of 66071920 is 2917066.

66071920 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 super-2 number, since 2×66071920² = 8730997224972800, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66071921) 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, 3552 + ... + 12031.

Almost surely, 2^66071920 is an apocalyptic number.

It is an amenable number.

66071920 is an abundant number, since it is smaller than the sum of its proper divisors (90453776).

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

66071920 is a wasteful number, since it uses less digits than its factorization.

66071920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15649 (or 15643 counting only the distinct ones).

The product of its (nonzero) digits is 4536, while the sum is 31.

The square root of 66071920 is about 8128.4635694576. The cubic root of 66071920 is about 404.2707396754.

Adding to 66071920 its reverse (2917066), we get a palindrome (68988986).

The spelling of 66071920 in words is "sixty-six million, seventy-one thousand, nine hundred twenty".