1260556921 has 4 divisors (see below), whose sum is σ = 1357522852. Its totient is φ = 1163590992.

The previous prime is 1260556907. The next prime is 1260556981. The reversal of 1260556921 is 1296550621.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1296550621 = 18047 ⋅71843.

It can be written as a sum of positive squares in 2 ways, for example, as 854977600 + 405579321 = 29240^2 + 20139^2 .

It is a cyclic number.

It is not a de Polignac number, because 1260556921 - 2¹¹ = 1260554873 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1260556901) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 48482946 + ... + 48482971.

It is an arithmetic number, because the mean of its divisors is an integer number (339380713).

Almost surely, 2^1260556921 is an apocalyptic number.

It is an amenable number.

1260556921 is a deficient number, since it is larger than the sum of its proper divisors (96965931).

1260556921 is an equidigital number, since it uses as much as digits as its factorization.

1260556921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 96965930.

The product of its (nonzero) digits is 32400, while the sum is 37.

The square root of 1260556921 is about 35504.3225678226. The cubic root of 1260556921 is about 1080.2414072265.

The spelling of 1260556921 in words is "one billion, two hundred sixty million, five hundred fifty-six thousand, nine hundred twenty-one".