1289969280 has 256 divisors, whose sum is σ = 4810320000. Its totient is φ = 325804032.

The previous prime is 1289969243. The next prime is 1289969309. The reversal of 1289969280 is 829699821.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 326356 + ... + 330284.

Almost surely, 2^1289969280 is an apocalyptic number.

1289969280 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 1289969280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2405160000).

1289969280 is an abundant number, since it is smaller than the sum of its proper divisors (3520350720).

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

1289969280 is a wasteful number, since it uses less digits than its factorization.

1289969280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3976 (or 3958 counting only the distinct ones).

The product of its (nonzero) digits is 1119744, while the sum is 54.

The square root of 1289969280 is about 35916.1423318262. The cubic root of 1289969280 is about 1088.5785921958.

The spelling of 1289969280 in words is "one billion, two hundred eighty-nine million, nine hundred sixty-nine thousand, two hundred eighty".