66569440 has 96 divisors (see below), whose sum is σ = 183556800. Its totient is φ = 22804992.

The previous prime is 66569417. The next prime is 66569443. The reversal of 66569440 is 4496566.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 66569393 and 66569402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66569443) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 54274 + ... + 55486.

It is an arithmetic number, because the mean of its divisors is an integer number (1912050).

Almost surely, 2^66569440 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 66569440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (91778400).

66569440 is an abundant number, since it is smaller than the sum of its proper divisors (116987360).

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

66569440 is a wasteful number, since it uses less digits than its factorization.

66569440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1249 (or 1227 counting only the distinct ones).

The product of its (nonzero) digits is 155520, while the sum is 40.

The square root of 66569440 is about 8159.0097438353. The cubic root of 66569440 is about 405.2829197265.

The spelling of 66569440 in words is "sixty-six million, five hundred sixty-nine thousand, four hundred forty".