1289673138 has 48 divisors (see below), whose sum is σ = 2852551296. Its totient is φ = 388365120.

The previous prime is 1289673137. The next prime is 1289673139. The reversal of 1289673138 is 8313769821.

It is an interprime number because it is at equal distance from previous prime (1289673137) and next prime (1289673139).

It is not an unprimeable number, because it can be changed into a prime (1289673137) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 34128 + ... + 61188.

It is an arithmetic number, because the mean of its divisors is an integer number (59428152).

Almost surely, 2^1289673138 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1289673138, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1426275648).

1289673138 is an abundant number, since it is smaller than the sum of its proper divisors (1562878158).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1289673138 is a wasteful number, since it uses less digits than its factorization.

1289673138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27139 (or 27126 counting only the distinct ones).

The product of its digits is 435456, while the sum is 48.

The square root of 1289673138 is about 35912.0194085490. The cubic root of 1289673138 is about 1088.4952831023.

The spelling of 1289673138 in words is "one billion, two hundred eighty-nine million, six hundred seventy-three thousand, one hundred thirty-eight".