12216781345 has 8 divisors (see below), whose sum is σ = 14699443176. Its totient is φ = 9747221376.

The previous prime is 12216781321. The next prime is 12216781403. The reversal of 12216781345 is 54318761221.

It can be written as a sum of positive squares in 4 ways, for example, as 879003904 + 11337777441 = 29648^2 + 106479^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 12216781345 - 2⁹ = 12216780833 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12216781298 and 12216781307.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3273412 + ... + 3277141.

It is an arithmetic number, because the mean of its divisors is an integer number (1837430397).

Almost surely, 2^12216781345 is an apocalyptic number.

It is an amenable number.

12216781345 is a deficient number, since it is larger than the sum of its proper divisors (2482661831).

12216781345 is an equidigital number, since it uses as much as digits as its factorization.

12216781345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6550931.

The product of its digits is 80640, while the sum is 40.

The spelling of 12216781345 in words is "twelve billion, two hundred sixteen million, seven hundred eighty-one thousand, three hundred forty-five".