66039720 has 64 divisors (see below), whose sum is σ = 199679040. Its totient is φ = 17472000.

The previous prime is 66039671. The next prime is 66039751. The reversal of 66039720 is 2793066.

It is a super-2 number, since 2×66039720² = 8722489235356800, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13620 + ... + 17820.

It is an arithmetic number, because the mean of its divisors is an integer number (3119985).

Almost surely, 2^66039720 is an apocalyptic number.

66039720 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 66039720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (99839520).

66039720 is an abundant number, since it is smaller than the sum of its proper divisors (133639320).

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

66039720 is a wasteful number, since it uses less digits than its factorization.

66039720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4346 (or 4342 counting only the distinct ones).

The product of its (nonzero) digits is 13608, while the sum is 33.

The square root of 66039720 is about 8126.4826339567. The cubic root of 66039720 is about 404.2050555286.

The spelling of 66039720 in words is "sixty-six million, thirty-nine thousand, seven hundred twenty".