1299278081 has 4 divisors (see below), whose sum is σ = 1302897600. Its totient is φ = 1295658564.

The previous prime is 1299278059. The next prime is 1299278087. The reversal of 1299278081 is 1808729921.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1808729921 = 21961 ⋅82361.

It is a cyclic number.

It is not a de Polignac number, because 1299278081 - 2²⁶ = 1232169217 is a prime.

It is a super-2 number, since 2×1299278081² = 3376247063534085122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1299278087) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1809221 + ... + 1809938.

It is an arithmetic number, because the mean of its divisors is an integer number (325724400).

Almost surely, 2^1299278081 is an apocalyptic number.

It is an amenable number.

1299278081 is a deficient number, since it is larger than the sum of its proper divisors (3619519).

1299278081 is an equidigital number, since it uses as much as digits as its factorization.

1299278081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3619518.

The product of its (nonzero) digits is 145152, while the sum is 47.

The square root of 1299278081 is about 36045.5001491171. The cubic root of 1299278081 is about 1091.1908207151.

The spelling of 1299278081 in words is "one billion, two hundred ninety-nine million, two hundred seventy-eight thousand, eighty-one".