1261503263 has 2 divisors, whose sum is σ = 1261503264. Its totient is φ = 1261503262.

The previous prime is 1261503251. The next prime is 1261503281. The reversal of 1261503263 is 3623051621.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1261503263 - 2⁴ = 1261503247 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1261503203) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 630751631 + 630751632.

It is an arithmetic number, because the mean of its divisors is an integer number (630751632).

Almost surely, 2^1261503263 is an apocalyptic number.

1261503263 is a deficient number, since it is larger than the sum of its proper divisors (1).

1261503263 is an equidigital number, since it uses as much as digits as its factorization.

1261503263 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6480, while the sum is 29.

The square root of 1261503263 is about 35517.6472052978. The cubic root of 1261503263 is about 1080.5116639900.

Adding to 1261503263 its reverse (3623051621), we get a palindrome (4884554884).

The spelling of 1261503263 in words is "one billion, two hundred sixty-one million, five hundred three thousand, two hundred sixty-three".