66402240 has 84 divisors (see below), whose sum is σ = 211631784. Its totient is φ = 17639936.

The previous prime is 66402239. The next prime is 66402251. The reversal of 66402240 is 4220466.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 66402240.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 252349 + ... + 252611.

It is an arithmetic number, because the mean of its divisors is an integer number (2519426).

Almost surely, 2^66402240 is an apocalyptic number.

66402240 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 66402240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (105815892).

66402240 is an abundant number, since it is smaller than the sum of its proper divisors (145229544).

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

66402240 is an equidigital number, since it uses as much as digits as its factorization.

66402240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 546 (or 273 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 24.

The square root of 66402240 is about 8148.7569604204. The cubic root of 66402240 is about 404.9433238782.

The spelling of 66402240 in words is "sixty-six million, four hundred two thousand, two hundred forty".