1280917999 has 2 divisors, whose sum is σ = 1280918000. Its totient is φ = 1280917998.

The previous prime is 1280917973. The next prime is 1280918017. The reversal of 1280917999 is 9997190821.

It is a strong prime.

It is an emirp because it is prime and its reverse (9997190821) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1280917999 - 2¹³ = 1280909807 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1280917919) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 640458999 + 640459000.

It is an arithmetic number, because the mean of its divisors is an integer number (640459000).

Almost surely, 2^1280917999 is an apocalyptic number.

1280917999 is a deficient number, since it is larger than the sum of its proper divisors (1).

1280917999 is an equidigital number, since it uses as much as digits as its factorization.

1280917999 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 734832, while the sum is 55.

The square root of 1280917999 is about 35789.9147665931. The cubic root of 1280917999 is about 1086.0265505121.

The spelling of 1280917999 in words is "one billion, two hundred eighty million, nine hundred seventeen thousand, nine hundred ninety-nine".