1213156823 has 2 divisors, whose sum is σ = 1213156824. Its totient is φ = 1213156822.

The previous prime is 1213156817. The next prime is 1213156843. The reversal of 1213156823 is 3286513121.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1213156823 - 2³⁰ = 139414999 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1213156823.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1213156843) 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 as a sum of consecutive naturals, namely, 606578411 + 606578412.

It is an arithmetic number, because the mean of its divisors is an integer number (606578412).

Almost surely, 2^1213156823 is an apocalyptic number.

1213156823 is a deficient number, since it is larger than the sum of its proper divisors (1).

1213156823 is an equidigital number, since it uses as much as digits as its factorization.

1213156823 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8640, while the sum is 32.

The square root of 1213156823 is about 34830.4008446644. The cubic root of 1213156823 is about 1066.5281311076.

Adding to 1213156823 its reverse (3286513121), we get a palindrome (4499669944).

The spelling of 1213156823 in words is "one billion, two hundred thirteen million, one hundred fifty-six thousand, eight hundred twenty-three".