66287920 has 40 divisors (see below), whose sum is σ = 159096960. Its totient is φ = 25658880.

The previous prime is 66287917. The next prime is 66287927. The reversal of 66287920 is 2978266.

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (40).

It is not an unprimeable number, because it can be changed into a prime (66287927) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10885 + ... + 15844.

It is an arithmetic number, because the mean of its divisors is an integer number (3977424).

Almost surely, 2^66287920 is an apocalyptic number.

It is an amenable number.

66287920 is an abundant number, since it is smaller than the sum of its proper divisors (92809040).

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

66287920 is a wasteful number, since it uses less digits than its factorization.

66287920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26773 (or 26767 counting only the distinct ones).

The product of its (nonzero) digits is 72576, while the sum is 40.

The square root of 66287920 is about 8141.7393719033. The cubic root of 66287920 is about 404.7108030439.

The spelling of 66287920 in words is "sixty-six million, two hundred eighty-seven thousand, nine hundred twenty".