1213355808 has 192 divisors, whose sum is σ = 4257792000. Its totient is φ = 328396032.

The previous prime is 1213355761. The next prime is 1213355809. The reversal of 1213355808 is 8085533121.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (1213355809) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 109633 + ... + 120191.

It is an arithmetic number, because the mean of its divisors is an integer number (22176000).

Almost surely, 2^1213355808 is an apocalyptic number.

1213355808 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1213355808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2128896000).

1213355808 is an abundant number, since it is smaller than the sum of its proper divisors (3044436192).

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

1213355808 is a wasteful number, since it uses less digits than its factorization.

1213355808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10604 (or 10590 counting only the distinct ones).

The product of its (nonzero) digits is 28800, while the sum is 36.

The square root of 1213355808 is about 34833.2572120380. The cubic root of 1213355808 is about 1066.5864394521.

Adding to 1213355808 its reverse (8085533121), we get a palindrome (9298888929).

The spelling of 1213355808 in words is "one billion, two hundred thirteen million, three hundred fifty-five thousand, eight hundred eight".