1066645399 has 4 divisors (see below), whose sum is σ = 1129389264. Its totient is φ = 1003901536.

The previous prime is 1066645379. The next prime is 1066645403. The reversal of 1066645399 is 9935466601.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9935466601 = 59 ⋅168397739.

It is a cyclic number.

It is not a de Polignac number, because 1066645399 - 2¹¹ = 1066643351 is a prime.

It is a super-2 number, since 2×1066645399² = 2275464814415738402, which contains 22 as substring.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1066645369) 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, 31371907 + ... + 31371940.

It is an arithmetic number, because the mean of its divisors is an integer number (282347316).

Almost surely, 2^1066645399 is an apocalyptic number.

1066645399 is a deficient number, since it is larger than the sum of its proper divisors (62743865).

1066645399 is an equidigital number, since it uses as much as digits as its factorization.

1066645399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62743864.

The product of its (nonzero) digits is 1049760, while the sum is 49.

The square root of 1066645399 is about 32659.5376421651. The cubic root of 1066645399 is about 1021.7391191406.

It can be divided in two parts, 10666 and 45399, that added together give a palindrome (56065).

The spelling of 1066645399 in words is "one billion, sixty-six million, six hundred forty-five thousand, three hundred ninety-nine".