1213162565 has 4 divisors (see below), whose sum is σ = 1455795084. Its totient is φ = 970530048.

The previous prime is 1213162541. The next prime is 1213162583. The reversal of 1213162565 is 5652613121.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 160224964 + 1052937601 = 12658^2 + 32449^2 .

It is a cyclic number.

It is not a de Polignac number, because 1213162565 - 2¹⁶ = 1213097029 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 121316252 + ... + 121316261.

It is an arithmetic number, because the mean of its divisors is an integer number (363948771).

Almost surely, 2^1213162565 is an apocalyptic number.

It is an amenable number.

1213162565 is a deficient number, since it is larger than the sum of its proper divisors (242632519).

1213162565 is an equidigital number, since it uses as much as digits as its factorization.

1213162565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 242632518.

The product of its digits is 10800, while the sum is 32.

The square root of 1213162565 is about 34830.4832725588. The cubic root of 1213162565 is about 1066.5298137685.

Adding to 1213162565 its reverse (5652613121), we get a palindrome (6865775686).

The spelling of 1213162565 in words is "one billion, two hundred thirteen million, one hundred sixty-two thousand, five hundred sixty-five".