1263517987 has 2 divisors, whose sum is σ = 1263517988. Its totient is φ = 1263517986.

The previous prime is 1263517919. The next prime is 1263518029. The reversal of 1263517987 is 7897153621.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1263517987 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1263517987.

It is not a weakly prime, because it can be changed into another prime (1263517187) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 631758993 + 631758994.

It is an arithmetic number, because the mean of its divisors is an integer number (631758994).

Almost surely, 2^1263517987 is an apocalyptic number.

1263517987 is a deficient number, since it is larger than the sum of its proper divisors (1).

1263517987 is an equidigital number, since it uses as much as digits as its factorization.

1263517987 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 635040, while the sum is 49.

The square root of 1263517987 is about 35545.9981854498. The cubic root of 1263517987 is about 1081.0865799017.

The spelling of 1263517987 in words is "one billion, two hundred sixty-three million, five hundred seventeen thousand, nine hundred eighty-seven".