1223456779 has 4 divisors (see below), whose sum is σ = 1276650576. Its totient is φ = 1170262984.

The previous prime is 1223456761. The next prime is 1223456807. The reversal of 1223456779 is 9776543221.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9776543221 = 31033 ⋅315037.

It is a cyclic number.

It is not a de Polignac number, because 1223456779 - 2¹⁵ = 1223424011 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 (1223456749) 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, 26596864 + ... + 26596909.

It is an arithmetic number, because the mean of its divisors is an integer number (319162644).

Almost surely, 2^1223456779 is an apocalyptic number.

1223456779 is a deficient number, since it is larger than the sum of its proper divisors (53193797).

1223456779 is an equidigital number, since it uses as much as digits as its factorization.

1223456779 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53193796.

The product of its digits is 635040, while the sum is 46.

The square root of 1223456779 is about 34977.9470380982. The cubic root of 1223456779 is about 1069.5379782452.

The spelling of 1223456779 in words is "one billion, two hundred twenty-three million, four hundred fifty-six thousand, seven hundred seventy-nine".