1326566644 has 72 divisors (see below), whose sum is σ = 2721820248. Its totient is φ = 561930240.

The previous prime is 1326566639. The next prime is 1326566707. The reversal of 1326566644 is 4466656231.

It can be written as a sum of positive squares in 12 ways, for example, as 721996900 + 604569744 = 26870^2 + 24588^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 1326566644.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 615072 + ... + 617224.

It is an arithmetic number, because the mean of its divisors is an integer number (37803059).

Almost surely, 2^1326566644 is an apocalyptic number.

It is an amenable number.

1326566644 is an abundant number, since it is smaller than the sum of its proper divisors (1395253604).

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

1326566644 is a wasteful number, since it uses less digits than its factorization.

1326566644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2245 (or 2226 counting only the distinct ones).

The product of its digits is 622080, while the sum is 43.

The square root of 1326566644 is about 36422.0625994740. The cubic root of 1326566644 is about 1098.7773312936. Note that the first 3 decimals are identical.

The spelling of 1326566644 in words is "one billion, three hundred twenty-six million, five hundred sixty-six thousand, six hundred forty-four".