66440260 has 12 divisors (see below), whose sum is σ = 139524588. Its totient is φ = 26576096.

The previous prime is 66440251. The next prime is 66440263. The reversal of 66440260 is 6204466.

It can be written as a sum of positive squares in 2 ways, for example, as 26193924 + 40246336 = 5118^2 + 6344^2 .

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 3 ways as a sum of consecutive naturals, for example, 1660987 + ... + 1661026.

It is an arithmetic number, because the mean of its divisors is an integer number (11627049).

Almost surely, 2^66440260 is an apocalyptic number.

It is an amenable number.

66440260 is an abundant number, since it is smaller than the sum of its proper divisors (73084328).

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

66440260 is a wasteful number, since it uses less digits than its factorization.

66440260 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3322022 (or 3322020 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 28.

The square root of 66440260 is about 8151.0894977297. The cubic root of 66440260 is about 405.0205954064.

The spelling of 66440260 in words is "sixty-six million, four hundred forty thousand, two hundred sixty".