1213135578 has 12 divisors (see below), whose sum is σ = 2628460458. Its totient is φ = 404378520.

The previous prime is 1213135577. The next prime is 1213135591. The reversal of 1213135578 is 8755313121.

It is a happy number.

1213135578 is a `hidden beast` number, since 1 + 21 + 31 + 35 + 578 = 666.

It can be written as a sum of positive squares in only one way, i.e., 1059697809 + 153437769 = 32553^2 + 12387^2 .

It is not an unprimeable number, because it can be changed into a prime (1213135571) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 33698193 + ... + 33698228.

Almost surely, 2^1213135578 is an apocalyptic number.

1213135578 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

1213135578 is an abundant number, since it is smaller than the sum of its proper divisors (1415324880).

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

1213135578 is a wasteful number, since it uses less digits than its factorization.

1213135578 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67396429 (or 67396426 counting only the distinct ones).

The product of its digits is 25200, while the sum is 36.

The square root of 1213135578 is about 34830.0958655011. The cubic root of 1213135578 is about 1066.5219053331.

Adding to 1213135578 its reverse (8755313121), we get a palindrome (9968448699).

The spelling of 1213135578 in words is "one billion, two hundred thirteen million, one hundred thirty-five thousand, five hundred seventy-eight".