1263779999 has 2 divisors, whose sum is σ = 1263780000. Its totient is φ = 1263779998.

The previous prime is 1263779987. The next prime is 1263780043. The reversal of 1263779999 is 9999773621.

It is a weak prime.

It is an emirp because it is prime and its reverse (9999773621) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1263779999 - 2⁸ = 1263779743 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1263779969) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 631889999 + 631890000.

It is an arithmetic number, because the mean of its divisors is an integer number (631890000).

Almost surely, 2^1263779999 is an apocalyptic number.

1263779999 is a deficient number, since it is larger than the sum of its proper divisors (1).

1263779999 is an equidigital number, since it uses as much as digits as its factorization.

1263779999 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11573604, while the sum is 62.

The square root of 1263779999 is about 35549.6835288305. The cubic root of 1263779999 is about 1081.1613019826.

The spelling of 1263779999 in words is "one billion, two hundred sixty-three million, seven hundred seventy-nine thousand, nine hundred ninety-nine".