1265213321 has 8 divisors (see below), whose sum is σ = 1345491720. Its totient is φ = 1185585408.

The previous prime is 1265213317. The next prime is 1265213353. The reversal of 1265213321 is 1233125621.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 435139600 + 830073721 = 20860^2 + 28811^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1265213321 - 2² = 1265213317 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1265210321) 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 7 ways as a sum of consecutive naturals, for example, 158606 + ... + 166391.

It is an arithmetic number, because the mean of its divisors is an integer number (168186465).

Almost surely, 2^1265213321 is an apocalyptic number.

It is an amenable number.

1265213321 is a deficient number, since it is larger than the sum of its proper divisors (80278399).

1265213321 is a wasteful number, since it uses less digits than its factorization.

1265213321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 325243.

The product of its digits is 2160, while the sum is 26.

The square root of 1265213321 is about 35569.8372360628. The cubic root of 1265213321 is about 1081.5698822738.

Adding to 1265213321 its reverse (1233125621), we get a palindrome (2498338942).

The spelling of 1265213321 in words is "one billion, two hundred sixty-five million, two hundred thirteen thousand, three hundred twenty-one".