1261260265 has 16 divisors (see below), whose sum is σ = 1563480576. Its totient is φ = 975744000.

The previous prime is 1261260229. The next prime is 1261260317. The reversal of 1261260265 is 5620621621.

It is not a de Polignac number, because 1261260265 - 2¹¹ = 1261258217 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 325590 + ... + 329440.

It is an arithmetic number, because the mean of its divisors is an integer number (97717536).

Almost surely, 2^1261260265 is an apocalyptic number.

It is an amenable number.

1261260265 is a deficient number, since it is larger than the sum of its proper divisors (302220311).

1261260265 is a wasteful number, since it uses less digits than its factorization.

1261260265 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6000.

The product of its (nonzero) digits is 8640, while the sum is 31.

The square root of 1261260265 is about 35514.2262340037. The cubic root of 1261260265 is about 1080.4422814151.

Adding to 1261260265 its reverse (5620621621), we get a palindrome (6881881886).

The spelling of 1261260265 in words is "one billion, two hundred sixty-one million, two hundred sixty thousand, two hundred sixty-five".