1289918649 has 16 divisors (see below), whose sum is σ = 1776360960. Its totient is φ = 831742080.

The previous prime is 1289918633. The next prime is 1289918653. The reversal of 1289918649 is 9468199821.

It is not a de Polignac number, because 1289918649 - 2⁴ = 1289918633 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1289918659) 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, 261397 + ... + 266285.

It is an arithmetic number, because the mean of its divisors is an integer number (111022560).

Almost surely, 2^1289918649 is an apocalyptic number.

It is an amenable number.

1289918649 is a deficient number, since it is larger than the sum of its proper divisors (486442311).

1289918649 is a wasteful number, since it uses less digits than its factorization.

1289918649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7760.

The product of its digits is 2239488, while the sum is 57.

The square root of 1289918649 is about 35915.4374747127. The cubic root of 1289918649 is about 1088.5643498556.

The spelling of 1289918649 in words is "one billion, two hundred eighty-nine million, nine hundred eighteen thousand, six hundred forty-nine".