66640896 has 132 divisors (see below), whose sum is σ = 220126192. Its totient is φ = 19021824.

The previous prime is 66640883. The next prime is 66640943. The reversal of 66640896 is 69804666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 63996 + ... + 65028.

Almost surely, 2^66640896 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 66640896, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (110063096).

66640896 is an abundant number, since it is smaller than the sum of its proper divisors (153485296).

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

66640896 is a wasteful number, since it uses less digits than its factorization.

66640896 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1066 (or 1045 counting only the distinct ones).

The product of its (nonzero) digits is 373248, while the sum is 45.

The square root of 66640896 is about 8163.3875321462. The cubic root of 66640896 is about 405.4278788378.

The spelling of 66640896 in words is "sixty-six million, six hundred forty thousand, eight hundred ninety-six".