1223456777789 has 4 divisors (see below), whose sum is σ = 1225039516956. Its totient is φ = 1221874038624.

The previous prime is 1223456777773. The next prime is 1223456777797. The reversal of 1223456777789 is 9877776543221.

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 682717155289 + 540739622500 = 826267^2 + 735350^2 .

It is a cyclic number.

It is not a de Polignac number, because 1223456777789 - 2⁴ = 1223456777773 is a prime.

It is a Duffinian number.

It is a plaindrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1223456777749) 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, 791368424 + ... + 791369969.

It is an arithmetic number, because the mean of its divisors is an integer number (306259879239).

Almost surely, 2^{1223456777789} is an apocalyptic number.

It is an amenable number.

1223456777789 is a deficient number, since it is larger than the sum of its proper divisors (1582739167).

1223456777789 is an equidigital number, since it uses as much as digits as its factorization.

1223456777789 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1582739166.

The product of its digits is 248935680, while the sum is 68.

The spelling of 1223456777789 in words is "one trillion, two hundred twenty-three billion, four hundred fifty-six million, seven hundred seventy-seven thousand, seven hundred eighty-nine".