66167640 has 432 divisors, whose sum is σ = 283832640. Its totient is φ = 13305600.

The previous prime is 66167639. The next prime is 66167641. The reversal of 66167640 is 4676166.

66167640 is a `hidden beast` number, since 6 + 6 + 1 + 6 + 7 + 640 = 666.

It is an interprime number because it is at equal distance from previous prime (66167639) and next prime (66167641).

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

It is a junction number, because it is equal to n+sod(n) for n = 66167595 and 66167604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66167641) by changing a digit.

It is a polite number, since it can be written in 107 ways as a sum of consecutive naturals, for example, 2134425 + ... + 2134455.

It is an arithmetic number, because the mean of its divisors is an integer number (657020).

Almost surely, 2^66167640 is an apocalyptic number.

66167640 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 66167640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (141916320).

66167640 is an abundant number, since it is smaller than the sum of its proper divisors (217665000).

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

66167640 is a wasteful number, since it uses less digits than its factorization.

66167640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84 (or 59 counting only the distinct ones).

The product of its (nonzero) digits is 36288, while the sum is 36.

The square root of 66167640 is about 8134.3493900865. The cubic root of 66167640 is about 404.4658710980.

The spelling of 66167640 in words is "sixty-six million, one hundred sixty-seven thousand, six hundred forty".