665814720 has 224 divisors, whose sum is σ = 2248692480. Its totient is φ = 166440960.

The previous prime is 665814697. The next prime is 665814727. The reversal of 665814720 is 27418566.

665814720 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (665814727) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3155415 + ... + 3155625.

Almost surely, 2^665814720 is an apocalyptic number.

665814720 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 665814720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1124346240).

665814720 is an abundant number, since it is smaller than the sum of its proper divisors (1582877760).

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

665814720 is a wasteful number, since it uses less digits than its factorization.

665814720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 423 (or 413 counting only the distinct ones).

The product of its (nonzero) digits is 80640, while the sum is 39.

The square root of 665814720 is about 25803.3858243448. The cubic root of 665814720 is about 873.2081841271.

The spelling of 665814720 in words is "six hundred sixty-five million, eight hundred fourteen thousand, seven hundred twenty".