1056509865 has 16 divisors (see below), whose sum is σ = 1878240000. Its totient is φ = 563471856.

The previous prime is 1056509843. The next prime is 1056509893. The reversal of 1056509865 is 5689056501.

It is a happy number.

1056509865 is a `hidden beast` number, since 1 + 0 + 565 + 0 + 9 + 86 + 5 = 666.

It is not a de Polignac number, because 1056509865 - 2⁷ = 1056509737 is a prime.

It is a super-2 number, since 2×1056509865² = 2232426189684636450, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 1056509865.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3912865 + ... + 3913134.

It is an arithmetic number, because the mean of its divisors is an integer number (117390000).

Almost surely, 2^1056509865 is an apocalyptic number.

1056509865 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1056509865 is a deficient number, since it is larger than the sum of its proper divisors (821730135).

1056509865 is an equidigital number, since it uses as much as digits as its factorization.

1056509865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7826013 (or 7826007 counting only the distinct ones).

The product of its (nonzero) digits is 324000, while the sum is 45.

The square root of 1056509865 is about 32503.9976772089. The cubic root of 1056509865 is about 1018.4925396544.

The spelling of 1056509865 in words is "one billion, fifty-six million, five hundred nine thousand, eight hundred sixty-five".