1261281280 has 224 divisors, whose sum is σ = 3567037824. Its totient is φ = 419168256.

The previous prime is 1261281193. The next prime is 1261281293. The reversal of 1261281280 is 821821621.

It is a tau number, because it is divible by the number of its divisors (224).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15196119 + ... + 15196201.

It is an arithmetic number, because the mean of its divisors is an integer number (15924276).

Almost surely, 2^1261281280 is an apocalyptic number.

1261281280 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 1261281280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1783518912).

1261281280 is an abundant number, since it is smaller than the sum of its proper divisors (2305756544).

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

1261281280 is an frugal number, since it uses more digits than its factorization.

1261281280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 174 (or 150 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 31.

The square root of 1261281280 is about 35514.5221001212. The cubic root of 1261281280 is about 1080.4482821244.

The spelling of 1261281280 in words is "one billion, two hundred sixty-one million, two hundred eighty-one thousand, two hundred eighty".