1261845578 has 16 divisors (see below), whose sum is σ = 2213471040. Its totient is φ = 528214176.

The previous prime is 1261845551. The next prime is 1261845623. The reversal of 1261845578 is 8755481621.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1047443 + ... + 1048646.

It is an arithmetic number, because the mean of its divisors is an integer number (138341940).

Almost surely, 2^1261845578 is an apocalyptic number.

1261845578 is a deficient number, since it is larger than the sum of its proper divisors (951625462).

1261845578 is a wasteful number, since it uses less digits than its factorization.

1261845578 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2096141.

The product of its digits is 537600, while the sum is 47.

The square root of 1261845578 is about 35522.4658209421. The cubic root of 1261845578 is about 1080.6093891698.

The spelling of 1261845578 in words is "one billion, two hundred sixty-one million, eight hundred forty-five thousand, five hundred seventy-eight".