66334640 has 40 divisors (see below), whose sum is σ = 155466240. Its totient is φ = 26320896.

The previous prime is 66334627. The next prime is 66334669. The reversal of 66334640 is 4643366.

It is a tau number, because it is divible by the number of its divisors (40).

It is a junction number, because it is equal to n+sod(n) for n = 66334597 and 66334606.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6896 + ... + 13424.

It is an arithmetic number, because the mean of its divisors is an integer number (3886656).

Almost surely, 2^66334640 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 66334640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (77733120).

66334640 is an abundant number, since it is smaller than the sum of its proper divisors (89131600).

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

66334640 is a wasteful number, since it uses less digits than its factorization.

66334640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6669 (or 6663 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 32.

The square root of 66334640 is about 8144.6080323119. The cubic root of 66334640 is about 404.8058613305.

The spelling of 66334640 in words is "sixty-six million, three hundred thirty-four thousand, six hundred forty".