1267799987 has 2 divisors, whose sum is σ = 1267799988. Its totient is φ = 1267799986.

The previous prime is 1267799977. The next prime is 1267799999. The reversal of 1267799987 is 7899977621.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1267799987 - 2⁴ = 1267799971 is a prime.

It is not a weakly prime, because it can be changed into another prime (1267799977) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 633899993 + 633899994.

It is an arithmetic number, because the mean of its divisors is an integer number (633899994).

Almost surely, 2^1267799987 is an apocalyptic number.

1267799987 is a deficient number, since it is larger than the sum of its proper divisors (1).

1267799987 is an equidigital number, since it uses as much as digits as its factorization.

1267799987 is an evil number, because the sum of its binary digits is even.

The product of its digits is 24004512, while the sum is 65.

The square root of 1267799987 is about 35606.1790564503. The cubic root of 1267799987 is about 1082.3064525681.

The spelling of 1267799987 in words is "one billion, two hundred sixty-seven million, seven hundred ninety-nine thousand, nine hundred eighty-seven".