1226778563 has 4 divisors (see below), whose sum is σ = 1247571480. Its totient is φ = 1205985648.

The previous prime is 1226778557. The next prime is 1226778571. The reversal of 1226778563 is 3658776221.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3658776221 = 23 ⋅159077227.

It is a cyclic number.

It is not a de Polignac number, because 1226778563 - 2⁴ = 1226778547 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1226078563) 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, 10396370 + ... + 10396487.

It is an arithmetic number, because the mean of its divisors is an integer number (311892870).

Almost surely, 2^1226778563 is an apocalyptic number.

1226778563 is a deficient number, since it is larger than the sum of its proper divisors (20792917).

1226778563 is an equidigital number, since it uses as much as digits as its factorization.

1226778563 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20792916.

The product of its digits is 846720, while the sum is 47.

The square root of 1226778563 is about 35025.3988271369. The cubic root of 1226778563 is about 1070.5050642073.

The spelling of 1226778563 in words is "one billion, two hundred twenty-six million, seven hundred seventy-eight thousand, five hundred sixty-three".