66687040 has 84 divisors (see below), whose sum is σ = 184768236. Its totient is φ = 22858752.

The previous prime is 66687011. The next prime is 66687053. The reversal of 66687040 is 4078666.

It can be written as a sum of positive squares in 2 ways, for example, as 14500864 + 52186176 = 3808^2 + 7224^2 .

It is a super-2 number, since 2×66687040² = 8894322607923200, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 13554 + ... + 17806.

Almost surely, 2^66687040 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66687040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (92384118).

66687040 is an abundant number, since it is smaller than the sum of its proper divisors (118081196).

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

66687040 is a wasteful number, since it uses less digits than its factorization.

66687040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4284 (or 4267 counting only the distinct ones).

The product of its (nonzero) digits is 48384, while the sum is 37.

The square root of 66687040 is about 8166.2133207503. The cubic root of 66687040 is about 405.5214337409.

The spelling of 66687040 in words is "sixty-six million, six hundred eighty-seven thousand, forty".