1289131890 has 32 divisors (see below), whose sum is σ = 3097664640. Its totient is φ = 343352064.

The previous prime is 1289131889. The next prime is 1289131897. The reversal of 1289131890 is 981319821.

It is a super-2 number, since 2×1289131890² = 3323722059629944200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1289131897) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 439 + ... + 50778.

It is an arithmetic number, because the mean of its divisors is an integer number (96802020).

Almost surely, 2^1289131890 is an apocalyptic number.

1289131890 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1289131890 is an abundant number, since it is smaller than the sum of its proper divisors (1808532750).

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

1289131890 is a wasteful number, since it uses less digits than its factorization.

1289131890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52066.

The product of its (nonzero) digits is 31104, while the sum is 42.

The square root of 1289131890 is about 35904.4828677423. The cubic root of 1289131890 is about 1088.3429891310.

The spelling of 1289131890 in words is "one billion, two hundred eighty-nine million, one hundred thirty-one thousand, eight hundred ninety".