66978288 has 120 divisors (see below), whose sum is σ = 207535328. Its totient is φ = 20030976.

The previous prime is 66978269. The next prime is 66978299. The reversal of 66978288 is 88287966.

It is a zygodrome in base 2.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 68781 + ... + 69747.

Almost surely, 2^66978288 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 66978288, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (103767664).

66978288 is an abundant number, since it is smaller than the sum of its proper divisors (140557040).

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

66978288 is a wasteful number, since it uses less digits than its factorization.

66978288 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1031 (or 1022 counting only the distinct ones).

The product of its digits is 2322432, while the sum is 54.

The square root of 66978288 is about 8184.0263929193. The cubic root of 66978288 is about 406.1109325024.

It can be divided in two parts, 66978 and 288, that multiplied together give a square (19289664 = 4392²).

The spelling of 66978288 in words is "sixty-six million, nine hundred seventy-eight thousand, two hundred eighty-eight".