1263863891 has 2 divisors, whose sum is σ = 1263863892. Its totient is φ = 1263863890.

The previous prime is 1263863863. The next prime is 1263863897. The reversal of 1263863891 is 1983683621.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1263863891 - 2¹⁰ = 1263862867 is a prime.

It is not a weakly prime, because it can be changed into another prime (1263863897) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 631931945 + 631931946.

It is an arithmetic number, because the mean of its divisors is an integer number (631931946).

Almost surely, 2^1263863891 is an apocalyptic number.

1263863891 is a deficient number, since it is larger than the sum of its proper divisors (1).

1263863891 is an equidigital number, since it uses as much as digits as its factorization.

1263863891 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 373248, while the sum is 47.

The square root of 1263863891 is about 35550.8634353654. The cubic root of 1263863891 is about 1081.1852246003.

The spelling of 1263863891 in words is "one billion, two hundred sixty-three million, eight hundred sixty-three thousand, eight hundred ninety-one".