66608640 has 360 divisors, whose sum is σ = 272895480. Its totient is φ = 14966784.

The previous prime is 66608627. The next prime is 66608681. The reversal of 66608640 is 4680666.

It is a tau number, because it is divible by the number of its divisors (360).

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

It is a junction number, because it is equal to n+sod(n) for n = 66608595 and 66608604.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 1128931 + ... + 1128989.

It is an arithmetic number, because the mean of its divisors is an integer number (758043).

Almost surely, 2^66608640 is an apocalyptic number.

66608640 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 66608640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (136447740).

66608640 is an abundant number, since it is smaller than the sum of its proper divisors (206286840).

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

66608640 is a wasteful number, since it uses less digits than its factorization.

66608640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102 (or 76 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 36.

The square root of 66608640 is about 8161.4116426020. The cubic root of 66608640 is about 405.3624555869.

The spelling of 66608640 in words is "sixty-six million, six hundred eight thousand, six hundred forty".