66440264 has 64 divisors (see below), whose sum is σ = 145152000. Its totient is φ = 28192320.

The previous prime is 66440263. The next prime is 66440273. The reversal of 66440264 is 46204466.

It is a self number, because there is not a number n which added to its sum of digits gives 66440264.

It is not an unprimeable number, because it can be changed into a prime (66440263) 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, 131837 + ... + 132339.

It is an arithmetic number, because the mean of its divisors is an integer number (2268000).

Almost surely, 2^66440264 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 66440264, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (72576000).

66440264 is an abundant number, since it is smaller than the sum of its proper divisors (78711736).

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

66440264 is a wasteful number, since it uses less digits than its factorization.

66440264 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 618 (or 614 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 32.

The square root of 66440264 is about 8151.0897430957. The cubic root of 66440264 is about 405.0206035345.

It can be divided in two parts, 664402 and 64, that added together give a palindrome (664466).

The spelling of 66440264 in words is "sixty-six million, four hundred forty thousand, two hundred sixty-four".