1261003560 has 256 divisors, whose sum is σ = 4157049600. Its totient is φ = 304791552.

The previous prime is 1261003547. The next prime is 1261003573. The reversal of 1261003560 is 653001621.

It is an interprime number because it is at equal distance from previous prime (1261003547) and next prime (1261003573).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 1261003560.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 11568786 + ... + 11568894.

It is an arithmetic number, because the mean of its divisors is an integer number (16238475).

Almost surely, 2^1261003560 is an apocalyptic number.

1261003560 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 1261003560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2078524800).

1261003560 is an abundant number, since it is smaller than the sum of its proper divisors (2896046040).

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

1261003560 is a wasteful number, since it uses less digits than its factorization.

1261003560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 300 (or 296 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 24.

The square root of 1261003560 is about 35510.6119350258. The cubic root of 1261003560 is about 1080.3689754363.

The spelling of 1261003560 in words is "one billion, two hundred sixty-one million, three thousand, five hundred sixty".