1291765280 has 96 divisors (see below), whose sum is σ = 3340754928. Its totient is φ = 469094400.

The previous prime is 1291765259. The next prime is 1291765283. The reversal of 1291765280 is 825671921.

It can be written as a sum of positive squares in 8 ways, for example, as 89340304 + 1202424976 = 9452^2 + 34676^2 .

It is a super-2 number, since 2×1291765280² = 3337315077226956800, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1291765283) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 121790 + ... + 131970.

Almost surely, 2^1291765280 is an apocalyptic number.

1291765280 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 1291765280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1670377464).

1291765280 is an abundant number, since it is smaller than the sum of its proper divisors (2048989648).

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

1291765280 is a wasteful number, since it uses less digits than its factorization.

1291765280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10270 (or 10262 counting only the distinct ones).

The product of its (nonzero) digits is 60480, while the sum is 41.

The square root of 1291765280 is about 35941.1363203781. The cubic root of 1291765280 is about 1089.0835604249.

The spelling of 1291765280 in words is "one billion, two hundred ninety-one million, seven hundred sixty-five thousand, two hundred eighty".