66666480 has 80 divisors (see below), whose sum is σ = 207739680. Its totient is φ = 17685504.

The previous prime is 66666437. The next prime is 66666487. The reversal of 66666480 is 8466666.

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66666487) 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, 54354 + ... + 55566.

It is an arithmetic number, because the mean of its divisors is an integer number (2596746).

Almost surely, 2^66666480 is an apocalyptic number.

66666480 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 66666480, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (103869840).

66666480 is an abundant number, since it is smaller than the sum of its proper divisors (141073200).

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

66666480 is a wasteful number, since it uses less digits than its factorization.

66666480 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1458 (or 1452 counting only the distinct ones).

The product of its (nonzero) digits is 248832, while the sum is 42.

The square root of 66666480 is about 8164.9543783171. The cubic root of 66666480 is about 405.4797545897.

The spelling of 66666480 in words is "sixty-six million, six hundred sixty-six thousand, four hundred eighty".