66870720 has 336 divisors, whose sum is σ = 273881088. Its totient is φ = 14653440.

The previous prime is 66870697. The next prime is 66870731. The reversal of 66870720 is 2707866.

It is a tau number, because it is divible by the number of its divisors (336).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 624907 + ... + 625013.

Almost surely, 2^66870720 is an apocalyptic number.

66870720 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 66870720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (136940544).

66870720 is an abundant number, since it is smaller than the sum of its proper divisors (207010368).

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

66870720 is a wasteful number, since it uses less digits than its factorization.

66870720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 168 (or 155 counting only the distinct ones).

The product of its (nonzero) digits is 28224, while the sum is 36.

The square root of 66870720 is about 8177.4519258752. The cubic root of 66870720 is about 405.8934095361.

The spelling of 66870720 in words is "sixty-six million, eight hundred seventy thousand, seven hundred twenty".