1265210321 has 2 divisors, whose sum is σ = 1265210322. Its totient is φ = 1265210320.

The previous prime is 1265210311. The next prime is 1265210339. The reversal of 1265210321 is 1230125621.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 805708225 + 459502096 = 28385^2 + 21436^2 .

It is a cyclic number.

It is not a de Polignac number, because 1265210321 - 2²² = 1261016017 is a prime.

It is not a weakly prime, because it can be changed into another prime (1265210311) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 632605160 + 632605161.

It is an arithmetic number, because the mean of its divisors is an integer number (632605161).

Almost surely, 2^1265210321 is an apocalyptic number.

It is an amenable number.

1265210321 is a deficient number, since it is larger than the sum of its proper divisors (1).

1265210321 is an equidigital number, since it uses as much as digits as its factorization.

1265210321 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 1265210321 is about 35569.7950654766. The cubic root of 1265210321 is about 1081.5690274214.

Adding to 1265210321 its reverse (1230125621), we get a palindrome (2495335942).

The spelling of 1265210321 in words is "one billion, two hundred sixty-five million, two hundred ten thousand, three hundred twenty-one".