1281297989 has 8 divisors (see below), whose sum is σ = 1288235520. Its totient is φ = 1274373216.

The previous prime is 1281297893. The next prime is 1281298033. The reversal of 1281297989 is 9897921821.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1281297989 - 2²⁴ = 1264520773 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 (1281297389) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 250742 + ... + 255800.

It is an arithmetic number, because the mean of its divisors is an integer number (161029440).

Almost surely, 2^1281297989 is an apocalyptic number.

It is an amenable number.

1281297989 is a deficient number, since it is larger than the sum of its proper divisors (6937531).

1281297989 is a wasteful number, since it uses less digits than its factorization.

1281297989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6379.

The product of its digits is 1306368, while the sum is 56.

The square root of 1281297989 is about 35795.2229913434. Note that the first 3 decimals coincide. The cubic root of 1281297989 is about 1086.1339314239.

The spelling of 1281297989 in words is "one billion, two hundred eighty-one million, two hundred ninety-seven thousand, nine hundred eighty-nine".