1066645391 has 8 divisors (see below), whose sum is σ = 1222160160. Its totient is φ = 911914848.

The previous prime is 1066645379. The next prime is 1066645403. The reversal of 1066645391 is 1935466601.

It is an interprime number because it is at equal distance from previous prime (1066645379) and next prime (1066645403).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1066645391 is a prime.

It is a super-2 number, since 2×1066645391² = 2275464780283085762, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1066645091) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 193136 + ... + 198581.

It is an arithmetic number, because the mean of its divisors is an integer number (152770020).

Almost surely, 2^1066645391 is an apocalyptic number.

1066645391 is a deficient number, since it is larger than the sum of its proper divisors (155514769).

1066645391 is an equidigital number, since it uses as much as digits as its factorization.

1066645391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 392113.

The product of its (nonzero) digits is 116640, while the sum is 41.

The square root of 1066645391 is about 32659.5375196894. The cubic root of 1066645391 is about 1021.7391165862.

The spelling of 1066645391 in words is "one billion, sixty-six million, six hundred forty-five thousand, three hundred ninety-one".