1281186720 has 720 divisors, whose sum is σ = 5353175520. Its totient is φ = 287400960.

The previous prime is 1281186707. The next prime is 1281186727. The reversal of 1281186720 is 276811821.

It is a tau number, because it is divible by the number of its divisors (720).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1281186727) by changing a digit.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 29795019 + ... + 29795061.

It is an arithmetic number, because the mean of its divisors is an integer number (7434966).

Almost surely, 2^1281186720 is an apocalyptic number.

1281186720 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 1281186720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2676587760).

1281186720 is an abundant number, since it is smaller than the sum of its proper divisors (4071988800).

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

1281186720 is a wasteful number, since it uses less digits than its factorization.

1281186720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111 (or 83 counting only the distinct ones).

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

The square root of 1281186720 is about 35793.6687138941. The cubic root of 1281186720 is about 1086.1024902510.

The spelling of 1281186720 in words is "one billion, two hundred eighty-one million, one hundred eighty-six thousand, seven hundred twenty".