1219778838 has 28 divisors (see below), whose sum is σ = 2743250748. Its totient is φ = 406592460.

The previous prime is 1219778809. The next prime is 1219778863. The reversal of 1219778838 is 8388779121.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 13 ways as a sum of consecutive naturals, for example, 416848 + ... + 419763.

It is an arithmetic number, because the mean of its divisors is an integer number (97973241).

Almost surely, 2^1219778838 is an apocalyptic number.

1219778838 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

1219778838 is an abundant number, since it is smaller than the sum of its proper divisors (1523471910).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1219778838 is an frugal number, since it uses more digits than its factorization.

1219778838 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 836631 (or 836616 counting only the distinct ones).

The product of its digits is 1354752, while the sum is 54.

The square root of 1219778838 is about 34925.3323248326. The cubic root of 1219778838 is about 1068.4651584403.

The spelling of 1219778838 in words is "one billion, two hundred nineteen million, seven hundred seventy-eight thousand, eight hundred thirty-eight".