1223556778 has 8 divisors (see below), whose sum is σ = 1840178880. Its totient is φ = 610163820.

The previous prime is 1223556767. The next prime is 1223556823. The reversal of 1223556778 is 8776553221.

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

It is a plaindrome in base 10.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 806338 + ... + 807853.

It is an arithmetic number, because the mean of its divisors is an integer number (230022360).

Almost surely, 2^1223556778 is an apocalyptic number.

1223556778 is a deficient number, since it is larger than the sum of its proper divisors (616622102).

1223556778 is a wasteful number, since it uses less digits than its factorization.

1223556778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1614572.

The product of its digits is 705600, while the sum is 46.

The square root of 1223556778 is about 34979.3764667125. The cubic root of 1223556778 is about 1069.5671169437.

The spelling of 1223556778 in words is "one billion, two hundred twenty-three million, five hundred fifty-six thousand, seven hundred seventy-eight".