66745889280 has 480 divisors, whose sum is σ = 265013109504. Its totient is φ = 15208316928.

The previous prime is 66745889263. The next prime is 66745889299. The reversal of 66745889280 is 8298854766.

It is a tau number, because it is divible by the number of its divisors (480).

It is a Harshad number since it is a multiple of its sum of digits (63).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 89832589 + ... + 89833331.

Almost surely, 2^66745889280 is an apocalyptic number.

66745889280 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 66745889280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (132506554752).

66745889280 is an abundant number, since it is smaller than the sum of its proper divisors (198267220224).

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

66745889280 is a wasteful number, since it uses less digits than its factorization.

66745889280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1336 (or 1317 counting only the distinct ones).

The product of its (nonzero) digits is 46448640, while the sum is 63.

The spelling of 66745889280 in words is "sixty-six billion, seven hundred forty-five million, eight hundred eighty-nine thousand, two hundred eighty".