1216764361 has 4 divisors (see below), whose sum is σ = 1216846800. Its totient is φ = 1216681924.

The previous prime is 1216764347. The next prime is 1216764379. The reversal of 1216764361 is 1634676121.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1216764361 is a prime.

It is a super-3 number, since 3×1216764361³ (a number of 28 digits) contains 333 as substring.

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 1216764361.

It is not an unprimeable number, because it can be changed into a prime (1216762361) by changing a digit.

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, 12331 + ... + 50848.

It is an arithmetic number, because the mean of its divisors is an integer number (304211700).

Almost surely, 2^1216764361 is an apocalyptic number.

It is an amenable number.

1216764361 is a deficient number, since it is larger than the sum of its proper divisors (82439).

1216764361 is an equidigital number, since it uses as much as digits as its factorization.

1216764361 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 82438.

The product of its digits is 36288, while the sum is 37.

The square root of 1216764361 is about 34882.1496040597. The cubic root of 1216764361 is about 1067.5842554254.

The spelling of 1216764361 in words is "one billion, two hundred sixteen million, seven hundred sixty-four thousand, three hundred sixty-one".