66706380 has 144 divisors (see below), whose sum is σ = 225650880. Its totient is φ = 15837696.

The previous prime is 66706363. The next prime is 66706391. The reversal of 66706380 is 8360766.

It is a happy number.

It is a super-2 number, since 2×66706380² = 8899482265408800, which contains 22 as substring.

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

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, 67369 + ... + 68351.

It is an arithmetic number, because the mean of its divisors is an integer number (1567020).

Almost surely, 2^66706380 is an apocalyptic number.

66706380 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 66706380, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (112825440).

66706380 is an abundant number, since it is smaller than the sum of its proper divisors (158944500).

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

66706380 is a wasteful number, since it uses less digits than its factorization.

66706380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1040 (or 1035 counting only the distinct ones).

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

The square root of 66706380 is about 8167.3973822755. The cubic root of 66706380 is about 405.5606318944.

The spelling of 66706380 in words is "sixty-six million, seven hundred six thousand, three hundred eighty".