66868884 has 36 divisors (see below), whose sum is σ = 170590420. Its totient is φ = 22083840.

The previous prime is 66868883. The next prime is 66868897. The reversal of 66868884 is 48886866.

It can be written as a sum of positive squares in 2 ways, for example, as 54464400 + 12404484 = 7380^2 + 3522^2 .

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 66868884.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66868883) 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, 4597 + ... + 12444.

Almost surely, 2^66868884 is an apocalyptic number.

It is an amenable number.

66868884 is an abundant number, since it is smaller than the sum of its proper divisors (103721536).

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

66868884 is a wasteful number, since it uses less digits than its factorization.

66868884 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17160 (or 17155 counting only the distinct ones).

The product of its digits is 3538944, while the sum is 54.

The square root of 66868884 is about 8177.3396651967. The cubic root of 66868884 is about 405.8896947706.

Subtracting from 66868884 its sum of digits (54), we obtain a triangular number (66868830 = T₁₁₅₆₄).

The spelling of 66868884 in words is "sixty-six million, eight hundred sixty-eight thousand, eight hundred eighty-four".