1165646565 has 32 divisors (see below), whose sum is σ = 2194162560. Its totient is φ = 585107712.

The previous prime is 1165646527. The next prime is 1165646579. The reversal of 1165646565 is 5656465611.

It is not a de Polignac number, because 1165646565 - 2⁸ = 1165646309 is a prime.

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

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1165646565.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 251659 + ... + 256248.

It is an arithmetic number, because the mean of its divisors is an integer number (68567580).

Almost surely, 2^1165646565 is an apocalyptic number.

1165646565 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1165646565 is a deficient number, since it is larger than the sum of its proper divisors (1028515995).

1165646565 is a wasteful number, since it uses less digits than its factorization.

1165646565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 507938 (or 507932 counting only the distinct ones).

The product of its digits is 648000, while the sum is 45.

The square root of 1165646565 is about 34141.5665282072. The cubic root of 1165646565 is about 1052.4196849512.

The spelling of 1165646565 in words is "one billion, one hundred sixty-five million, six hundred forty-six thousand, five hundred sixty-five".