66648540 has 96 divisors (see below), whose sum is σ = 215792640. Its totient is φ = 15054336.

The previous prime is 66648521. The next prime is 66648553. The reversal of 66648540 is 4584666.

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, 36489 + ... + 38271.

It is an arithmetic number, because the mean of its divisors is an integer number (2247840).

Almost surely, 2^66648540 is an apocalyptic number.

66648540 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 66648540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (107896320).

66648540 is an abundant number, since it is smaller than the sum of its proper divisors (149144100).

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

66648540 is a wasteful number, since it uses less digits than its factorization.

66648540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1891 (or 1889 counting only the distinct ones).

The product of its (nonzero) digits is 138240, while the sum is 39.

The square root of 66648540 is about 8163.8557067111. The cubic root of 66648540 is about 405.4433796909.

The spelling of 66648540 in words is "sixty-six million, six hundred forty-eight thousand, five hundred forty".