66365440 has 48 divisors (see below), whose sum is σ = 159262740. Its totient is φ = 26542080.

The previous prime is 66365437. The next prime is 66365447. The reversal of 66365440 is 4456366.

It can be written as a sum of positive squares in 2 ways, for example, as 63489024 + 2876416 = 7968^2 + 1696^2 .

It is a junction number, because it is equal to n+sod(n) for n = 66365396 and 66365405.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66365447) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7000 + ... + 13480.

Almost surely, 2^66365440 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66365440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (79631370).

66365440 is an abundant number, since it is smaller than the sum of its proper divisors (92897300).

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

66365440 is an equidigital number, since it uses as much as digits as its factorization.

66365440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6508 (or 6488 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 34.

The square root of 66365440 is about 8146.4986343827. The cubic root of 66365440 is about 404.8685037716.

The spelling of 66365440 in words is "sixty-six million, three hundred sixty-five thousand, four hundred forty".