66819744 has 36 divisors (see below), whose sum is σ = 190019466. Its totient is φ = 22273152.

The previous prime is 66819737. The next prime is 66819749. The reversal of 66819744 is 44791866.

It can be written as a sum of positive squares in only one way, i.e., 49280400 + 17539344 = 7020^2 + 4188^2 .

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

It is a self number, because there is not a number n which added to its sum of digits gives 66819744.

It is not an unprimeable number, because it can be changed into a prime (66819749) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 115719 + ... + 116294.

Almost surely, 2^66819744 is an apocalyptic number.

It is an amenable number.

66819744 is an abundant number, since it is smaller than the sum of its proper divisors (123199722).

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

66819744 is a wasteful number, since it uses less digits than its factorization.

66819744 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 232029 (or 232018 counting only the distinct ones).

The product of its digits is 290304, while the sum is 45.

The square root of 66819744 is about 8174.3344683222. The cubic root of 66819744 is about 405.7902448911.

The spelling of 66819744 in words is "sixty-six million, eight hundred nineteen thousand, seven hundred forty-four".