1289198400 has 672 divisors, whose sum is σ = 5342729472. Its totient is φ = 265420800.

The previous prime is 1289198399. The next prime is 1289198401. The reversal of 1289198400 is 48919821.

It is an interprime number because it is at equal distance from previous prime (1289198399) and next prime (1289198401).

It is a tau number, because it is divible by the number of its divisors (672).

It is a hoax number, since the sum of its digits (42) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1289198401) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 21134370 + ... + 21134430.

Almost surely, 2^1289198400 is an apocalyptic number.

1289198400 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 1289198400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2671364736).

1289198400 is an abundant number, since it is smaller than the sum of its proper divisors (4053531072).

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

1289198400 is a wasteful number, since it uses less digits than its factorization.

1289198400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 147 (or 132 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 42.

The square root of 1289198400 is about 35905.4090632595. The cubic root of 1289198400 is about 1088.3617057180.

The spelling of 1289198400 in words is "one billion, two hundred eighty-nine million, one hundred ninety-eight thousand, four hundred".