66104640 has 224 divisors, whose sum is σ = 266760960. Its totient is φ = 15095808.

The previous prime is 66104611. The next prime is 66104657. The reversal of 66104640 is 4640166.

66104640 is a `hidden beast` number, since 6 + 6 + 10 + 4 + 640 = 666.

It is a tau number, because it is divible by the number of its divisors (224).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 59934 + ... + 61026.

Almost surely, 2^66104640 is an apocalyptic number.

66104640 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 66104640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (133380480).

66104640 is an abundant number, since it is smaller than the sum of its proper divisors (200656320).

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

66104640 is a wasteful number, since it uses less digits than its factorization.

66104640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1126 (or 1110 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

The square root of 66104640 is about 8130.4760008255. The cubic root of 66104640 is about 404.3374627032.

The spelling of 66104640 in words is "sixty-six million, one hundred four thousand, six hundred forty".