1295999999 has 16 divisors (see below), whose sum is σ = 1532160000. Its totient is φ = 1073028384.

The previous prime is 1295999987. The next prime is 1296000011. The reversal of 1295999999 is 9999995921.

It is a Cunningham number, because it is equal to 36000²-1.

It is an interprime number because it is at equal distance from previous prime (1295999987) and next prime (1296000011).

It is a cyclic number.

It is not a de Polignac number, because 1295999999 - 2²⁰ = 1294951423 is a prime.

1295999999 is a modest number, since divided by 99999 gives 12959 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1295999099) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18002 + ... + 54000.

It is an arithmetic number, because the mean of its divisors is an integer number (95760000).

Almost surely, 2^1295999999 is an apocalyptic number.

1295999999 is a deficient number, since it is larger than the sum of its proper divisors (236160001).

1295999999 is a wasteful number, since it uses less digits than its factorization.

1295999999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36182.

The product of its digits is 47829690, while the sum is 71.

The square root of 1295999999 is about 35999.9999861111. Note that the first 4 decimals coincide. The cubic root of 1295999999 is about 1090.2723554189.

The spelling of 1295999999 in words is "one billion, two hundred ninety-five million, nine hundred ninety-nine thousand, nine hundred ninety-nine".