66573661 has 16 divisors (see below), whose sum is σ = 86611968. Its totient is φ = 49618800.

The previous prime is 66573641. The next prime is 66573673. The reversal of 66573661 is 16637566.

It is not a de Polignac number, because 66573661 - 2⁵ = 66573629 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66573641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17025 + ... + 20566.

It is an arithmetic number, because the mean of its divisors is an integer number (5413248).

Almost surely, 2^66573661 is an apocalyptic number.

It is an amenable number.

66573661 is a deficient number, since it is larger than the sum of its proper divisors (20038307).

66573661 is a wasteful number, since it uses less digits than its factorization.

66573661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37632.

The product of its digits is 136080, while the sum is 40.

The square root of 66573661 is about 8159.2684108319. The cubic root of 66573661 is about 405.2914855341.

The spelling of 66573661 in words is "sixty-six million, five hundred seventy-three thousand, six hundred sixty-one".