66678120 has 128 divisors (see below), whose sum is σ = 224726400. Its totient is φ = 17584128.

The previous prime is 66678119. The next prime is 66678121. The reversal of 66678120 is 2187666.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (66678119) and next prime (66678121).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (66678121) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 115272 + ... + 115848.

It is an arithmetic number, because the mean of its divisors is an integer number (1755675).

Almost surely, 2^66678120 is an apocalyptic number.

66678120 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66678120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (112363200).

66678120 is an abundant number, since it is smaller than the sum of its proper divisors (158048280).

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

66678120 is a wasteful number, since it uses less digits than its factorization.

66678120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 704 (or 694 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 36.

The square root of 66678120 is about 8165.6671497190. The cubic root of 66678120 is about 405.5033522042.

The spelling of 66678120 in words is "sixty-six million, six hundred seventy-eight thousand, one hundred twenty".