66688908 has 72 divisors (see below), whose sum is σ = 184248624. Its totient is φ = 18648960.

The previous prime is 66688903. The next prime is 66688957. The reversal of 66688908 is 80988666.

It is not an unprimeable number, because it can be changed into a prime (66688903) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 17110 + ... + 20642.

Almost surely, 2^66688908 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66688908, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (92124312).

66688908 is an abundant number, since it is smaller than the sum of its proper divisors (117559716).

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

66688908 is a wasteful number, since it uses less digits than its factorization.

66688908 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3575 (or 3562 counting only the distinct ones).

The product of its (nonzero) digits is 995328, while the sum is 51.

The square root of 66688908 is about 8166.3276936454. The cubic root of 66688908 is about 405.5252201186.

It can be divided in two parts, 6668 and 8908, that added together give a triangular number (15576 = T₁₇₆).

The spelling of 66688908 in words is "sixty-six million, six hundred eighty-eight thousand, nine hundred eight".