1289282640 has 40 divisors (see below), whose sum is σ = 3996776928. Its totient is φ = 343808640.

The previous prime is 1289282623. The next prime is 1289282647. The reversal of 1289282640 is 462829821.

It is a tau number, because it is divible by the number of its divisors (40).

It is a junction number, because it is equal to n+sod(n) for n = 1289282592 and 1289282601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1289282647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2685766 + ... + 2686245.

Almost surely, 2^1289282640 is an apocalyptic number.

1289282640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1289282640 is an abundant number, since it is smaller than the sum of its proper divisors (2707494288).

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

1289282640 is a wasteful number, since it uses less digits than its factorization.

1289282640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5372027 (or 5372021 counting only the distinct ones).

The product of its (nonzero) digits is 110592, while the sum is 42.

The square root of 1289282640 is about 35906.5821264013. The cubic root of 1289282640 is about 1088.3854107823.

The spelling of 1289282640 in words is "one billion, two hundred eighty-nine million, two hundred eighty-two thousand, six hundred forty".