1216154365 has 4 divisors (see below), whose sum is σ = 1459385244. Its totient is φ = 972923488.

The previous prime is 1216154339. The next prime is 1216154431. The reversal of 1216154365 is 5634516121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5634516121 = 13 ⋅433424317.

It can be written as a sum of positive squares in 2 ways, for example, as 950920569 + 265233796 = 30837^2 + 16286^2 .

It is a cyclic number.

It is not a de Polignac number, because 1216154365 - 2⁹ = 1216153853 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1216154365.

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 3 ways as a sum of consecutive naturals, for example, 121615432 + ... + 121615441.

It is an arithmetic number, because the mean of its divisors is an integer number (364846311).

Almost surely, 2^1216154365 is an apocalyptic number.

It is an amenable number.

1216154365 is a deficient number, since it is larger than the sum of its proper divisors (243230879).

1216154365 is an equidigital number, since it uses as much as digits as its factorization.

1216154365 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 243230878.

The product of its digits is 21600, while the sum is 34.

The square root of 1216154365 is about 34873.4048380711. The cubic root of 1216154365 is about 1067.4058229089.

The spelling of 1216154365 in words is "one billion, two hundred sixteen million, one hundred fifty-four thousand, three hundred sixty-five".