66878568 has 32 divisors (see below), whose sum is σ = 185774400. Its totient is φ = 22292784.

The previous prime is 66878557. The next prime is 66878569. The reversal of 66878568 is 86587866.

66878568 is a `hidden beast` number, since 6 + 6 + 8 + 78 + 568 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (66878569) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 154596 + ... + 155027.

It is an arithmetic number, because the mean of its divisors is an integer number (5805450).

Almost surely, 2^66878568 is an apocalyptic number.

It is an amenable number.

66878568 is an abundant number, since it is smaller than the sum of its proper divisors (118895832).

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

66878568 is a wasteful number, since it uses less digits than its factorization.

66878568 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 309638 (or 309628 counting only the distinct ones).

The product of its digits is 3870720, while the sum is 54.

The square root of 66878568 is about 8177.9317678738. The cubic root of 66878568 is about 405.9092875709.

The spelling of 66878568 in words is "sixty-six million, eight hundred seventy-eight thousand, five hundred sixty-eight".