1289536920 has 288 divisors, whose sum is σ = 4996948320. Its totient is φ = 287400960.

The previous prime is 1289536891. The next prime is 1289536949. The reversal of 1289536920 is 296359821.

1289536920 is a `hidden beast` number, since 1 + 28 + 9 + 536 + 92 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (1289536891) and next prime (1289536949).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 722349 + ... + 724131.

It is an arithmetic number, because the mean of its divisors is an integer number (17350515).

Almost surely, 2^1289536920 is an apocalyptic number.

1289536920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1289536920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2498474160).

1289536920 is an abundant number, since it is smaller than the sum of its proper divisors (3707411400).

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

1289536920 is a wasteful number, since it uses less digits than its factorization.

1289536920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1855 (or 1841 counting only the distinct ones).

The product of its (nonzero) digits is 233280, while the sum is 45.

The square root of 1289536920 is about 35910.1228068076. The cubic root of 1289536920 is about 1088.4569586962.

The spelling of 1289536920 in words is "one billion, two hundred eighty-nine million, five hundred thirty-six thousand, nine hundred twenty".