66545280 has 128 divisors (see below), whose sum is σ = 235742400. Its totient is φ = 17740800.

The previous prime is 66545273. The next prime is 66545287. The reversal of 66545280 is 8254566.

It is an interprime number because it is at equal distance from previous prime (66545273) and next prime (66545287).

It is a tau number, because it is divible by the number of its divisors (128).

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

It is not an unprimeable number, because it can be changed into a prime (66545287) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15355 + ... + 19205.

Almost surely, 2^66545280 is an apocalyptic number.

66545280 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 66545280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (117871200).

66545280 is an abundant number, since it is smaller than the sum of its proper divisors (169197120).

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

66545280 is a wasteful number, since it uses less digits than its factorization.

66545280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3879 (or 3861 counting only the distinct ones).

The product of its (nonzero) digits is 57600, while the sum is 36.

The square root of 66545280 is about 8157.5290376437. The cubic root of 66545280 is about 405.2338841123.

The spelling of 66545280 in words is "sixty-six million, five hundred forty-five thousand, two hundred eighty".