66945554 has 16 divisors (see below), whose sum is σ = 111632640. Its totient is φ = 29900880.

The previous prime is 66945553. The next prime is 66945581. The reversal of 66945554 is 45554966.

66945554 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 (66945553) 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, 40724 + ... + 42335.

It is an arithmetic number, because the mean of its divisors is an integer number (6977040).

Almost surely, 2^66945554 is an apocalyptic number.

66945554 is a deficient number, since it is larger than the sum of its proper divisors (44687086).

66945554 is a wasteful number, since it uses less digits than its factorization.

66945554 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83105.

The product of its digits is 648000, while the sum is 44.

The square root of 66945554 is about 8182.0262771516. The cubic root of 66945554 is about 406.0447627933.

The spelling of 66945554 in words is "sixty-six million, nine hundred forty-five thousand, five hundred fifty-four".