66640912 has 20 divisors (see below), whose sum is σ = 139049260. Its totient is φ = 30757248.

The previous prime is 66640883. The next prime is 66640943. The reversal of 66640912 is 21904666.

66640912 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 35236096 + 31404816 = 5936^2 + 5604^2 .

It is a super-2 number, since 2×66640912² = 8882022304383488, which contains 22 as substring.

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 3 ways as a sum of consecutive naturals, for example, 159987 + ... + 160402.

It is an arithmetic number, because the mean of its divisors is an integer number (6952463).

Almost surely, 2^66640912 is an apocalyptic number.

It is an amenable number.

66640912 is an abundant number, since it is smaller than the sum of its proper divisors (72408348).

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

66640912 is a wasteful number, since it uses less digits than its factorization.

66640912 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 320410 (or 320404 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 34.

The square root of 66640912 is about 8163.3885121315. The cubic root of 66640912 is about 405.4279112845.

The spelling of 66640912 in words is "sixty-six million, six hundred forty thousand, nine hundred twelve".