66523240 has 64 divisors (see below), whose sum is σ = 172085760. Its totient is φ = 22671360.

The previous prime is 66523231. The next prime is 66523243. The reversal of 66523240 is 4232566.

It is a happy number.

66523240 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a junction number, because it is equal to n+sod(n) for n = 66523199 and 66523208.

It is not an unprimeable number, because it can be changed into a prime (66523243) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 53425 + ... + 54655.

It is an arithmetic number, because the mean of its divisors is an integer number (2688840).

Almost surely, 2^66523240 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 66523240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (86042880).

66523240 is an abundant number, since it is smaller than the sum of its proper divisors (105562520).

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

66523240 is a wasteful number, since it uses less digits than its factorization.

66523240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1442 (or 1438 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 28.

The square root of 66523240 is about 8156.1780265024. The cubic root of 66523240 is about 405.1891409388.

The spelling of 66523240 in words is "sixty-six million, five hundred twenty-three thousand, two hundred forty".