1263041261 has 4 divisors (see below), whose sum is σ = 1284448800. Its totient is φ = 1241633724.

The previous prime is 1263041257. The next prime is 1263041267. The reversal of 1263041261 is 1621403621.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1621403621 = 29599 ⋅54779.

It is a cyclic number.

It is not a de Polignac number, because 1263041261 - 2² = 1263041257 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1263041261.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1263041267) 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 3 ways as a sum of consecutive naturals, for example, 10703681 + ... + 10703798.

It is an arithmetic number, because the mean of its divisors is an integer number (321112200).

Almost surely, 2^1263041261 is an apocalyptic number.

It is an amenable number.

1263041261 is a deficient number, since it is larger than the sum of its proper divisors (21407539).

1263041261 is an equidigital number, since it uses as much as digits as its factorization.

1263041261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21407538.

The product of its (nonzero) digits is 1728, while the sum is 26.

The square root of 1263041261 is about 35539.2917909178. The cubic root of 1263041261 is about 1080.9505979535.

Adding to 1263041261 its reverse (1621403621), we get a palindrome (2884444882).

The spelling of 1263041261 in words is "one billion, two hundred sixty-three million, forty-one thousand, two hundred sixty-one".