66545880 has 64 divisors (see below), whose sum is σ = 201731040. Its totient is φ = 17559552.

The previous prime is 66545819. The next prime is 66545893. The reversal of 66545880 is 8854566.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8782 + ... + 14498.

Almost surely, 2^66545880 is an apocalyptic number.

66545880 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 66545880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (100865520).

66545880 is an abundant number, since it is smaller than the sum of its proper divisors (135185160).

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

66545880 is a wasteful number, since it uses less digits than its factorization.

66545880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5828 (or 5824 counting only the distinct ones).

The product of its (nonzero) digits is 230400, while the sum is 42.

The square root of 66545880 is about 8157.5658134029. The cubic root of 66545880 is about 405.2351020279.

The spelling of 66545880 in words is "sixty-six million, five hundred forty-five thousand, eight hundred eighty".