1287861120 has 864 divisors, whose sum is σ = 5809232520. Its totient is φ = 271724544.

The previous prime is 1287861079. The next prime is 1287861139. The reversal of 1287861120 is 211687821.

1287861120 is a `hidden beast` number, since 12 + 8 + 7 + 8 + 611 + 20 = 666.

It is a tau number, because it is divible by the number of its divisors (864).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 107 ways as a sum of consecutive naturals, for example, 99066234 + ... + 99066246.

Almost surely, 2^1287861120 is an apocalyptic number.

1287861120 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 1287861120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2904616260).

1287861120 is an abundant number, since it is smaller than the sum of its proper divisors (4521371400).

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

1287861120 is an equidigital number, since it uses as much as digits as its factorization.

1287861120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74 (or 30 counting only the distinct ones).

The product of its (nonzero) digits is 10752, while the sum is 36.

The square root of 1287861120 is about 35886.7819677385. The cubic root of 1287861120 is about 1087.9852578741.

The spelling of 1287861120 in words is "one billion, two hundred eighty-seven million, eight hundred sixty-one thousand, one hundred twenty".