1289278997 has 12 divisors (see below), whose sum is σ = 1376136096. Its totient is φ = 1207631040.

The previous prime is 1289278993. The next prime is 1289279021. The reversal of 1289278997 is 7998729821.

It is a happy number.

It is not a de Polignac number, because 1289278997 - 2² = 1289278993 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1289278993) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 50408 + ... + 71550.

It is an arithmetic number, because the mean of its divisors is an integer number (114678008).

Almost surely, 2^1289278997 is an apocalyptic number.

1289278997 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

It is an amenable number.

1289278997 is a deficient number, since it is larger than the sum of its proper divisors (86857099).

1289278997 is a wasteful number, since it uses less digits than its factorization.

1289278997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21388 (or 21371 counting only the distinct ones).

The product of its digits is 9144576, while the sum is 62.

The square root of 1289278997 is about 35906.5313975048. The cubic root of 1289278997 is about 1088.3843856666.

The spelling of 1289278997 in words is "one billion, two hundred eighty-nine million, two hundred seventy-eight thousand, nine hundred ninety-seven".