1216231529 has 2 divisors, whose sum is σ = 1216231530. Its totient is φ = 1216231528.

The previous prime is 1216231433. The next prime is 1216231537. The reversal of 1216231529 is 9251326121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 738371929 + 477859600 = 27173^2 + 21860^2 .

It is an emirp because it is prime and its reverse (9251326121) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1216231529 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1216231495 and 1216231504.

It is not a weakly prime, because it can be changed into another prime (1216231589) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 608115764 + 608115765.

It is an arithmetic number, because the mean of its divisors is an integer number (608115765).

Almost surely, 2^1216231529 is an apocalyptic number.

It is an amenable number.

1216231529 is a deficient number, since it is larger than the sum of its proper divisors (1).

1216231529 is an equidigital number, since it uses as much as digits as its factorization.

1216231529 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6480, while the sum is 32.

The square root of 1216231529 is about 34874.5111650328. The cubic root of 1216231529 is about 1067.4283977737.

The spelling of 1216231529 in words is "one billion, two hundred sixteen million, two hundred thirty-one thousand, five hundred twenty-nine".