66289920 has 144 divisors (see below), whose sum is σ = 215944512. Its totient is φ = 17326080.

The previous prime is 66289901. The next prime is 66289921. The reversal of 66289920 is 2998266.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66289921) 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, 234099 + ... + 234381.

Almost surely, 2^66289920 is an apocalyptic number.

66289920 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 66289920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (107972256).

66289920 is an abundant number, since it is smaller than the sum of its proper divisors (149654592).

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

66289920 is a wasteful number, since it uses less digits than its factorization.

66289920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 368 (or 354 counting only the distinct ones).

The product of its (nonzero) digits is 93312, while the sum is 42.

The square root of 66289920 is about 8141.8621948544. The cubic root of 66289920 is about 404.7148732348.

The spelling of 66289920 in words is "sixty-six million, two hundred eighty-nine thousand, nine hundred twenty".