66541644 has 36 divisors (see below), whose sum is σ = 181142416. Its totient is φ = 20474208.

The previous prime is 66541627. The next prime is 66541649. The reversal of 66541644 is 44614566.

66541644 is a `hidden beast` number, since 6 + 6 + 5 + 4 + 1 + 644 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 66541599 and 66541608.

It is not an unprimeable number, because it can be changed into a prime (66541649) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 70624 + ... + 71559.

Almost surely, 2^66541644 is an apocalyptic number.

It is an amenable number.

66541644 is an abundant number, since it is smaller than the sum of its proper divisors (114600772).

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

66541644 is a wasteful number, since it uses less digits than its factorization.

66541644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 142206 (or 142201 counting only the distinct ones).

The product of its digits is 69120, while the sum is 36.

The square root of 66541644 is about 8157.3061729961. The cubic root of 66541644 is about 405.2265033873.

The spelling of 66541644 in words is "sixty-six million, five hundred forty-one thousand, six hundred forty-four".