1263787391 has 2 divisors, whose sum is σ = 1263787392. Its totient is φ = 1263787390.

The previous prime is 1263787331. The next prime is 1263787409. The reversal of 1263787391 is 1937873621.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1263787391 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1263787331) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 631893695 + 631893696.

It is an arithmetic number, because the mean of its divisors is an integer number (631893696).

Almost surely, 2^1263787391 is an apocalyptic number.

1263787391 is a deficient number, since it is larger than the sum of its proper divisors (1).

1263787391 is an equidigital number, since it uses as much as digits as its factorization.

1263787391 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 381024, while the sum is 47.

The square root of 1263787391 is about 35549.7874958487. The cubic root of 1263787391 is about 1081.1634099257.

The spelling of 1263787391 in words is "one billion, two hundred sixty-three million, seven hundred eighty-seven thousand, three hundred ninety-one".