1223444556779 has 4 divisors (see below), whose sum is σ = 1235322659376. Its totient is φ = 1211566454184.

The previous prime is 1223444556757. The next prime is 1223444556787. The reversal of 1223444556779 is 9776554443221.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1223444556779 is a prime.

It is a Duffinian number.

It is a plaindrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (1223444556979) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5939051144 + ... + 5939051349.

It is an arithmetic number, because the mean of its divisors is an integer number (308830664844).

Almost surely, 2^{1223444556779} is an apocalyptic number.

1223444556779 is a deficient number, since it is larger than the sum of its proper divisors (11878102597).

1223444556779 is a wasteful number, since it uses less digits than its factorization.

1223444556779 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11878102596.

The product of its digits is 50803200, while the sum is 59.

The spelling of 1223444556779 in words is "one trillion, two hundred twenty-three billion, four hundred forty-four million, five hundred fifty-six thousand, seven hundred seventy-nine".