2600243561 has 4 divisors (see below), whose sum is σ = 2670520452. Its totient is φ = 2529966672.

The previous prime is 2600243543. The next prime is 2600243563. The reversal of 2600243561 is 1653420062.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1453134400 + 1147109161 = 38120^2 + 33869^2 .

It is a cyclic number.

It is not a de Polignac number, because 2600243561 - 2¹⁴ = 2600227177 is a prime.

It is a super-2 number, since 2×2600243561² = 13522533153043921442, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2600243563) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 35138390 + ... + 35138463.

It is an arithmetic number, because the mean of its divisors is an integer number (667630113).

Almost surely, 2^2600243561 is an apocalyptic number.

It is an amenable number.

2600243561 is a deficient number, since it is larger than the sum of its proper divisors (70276891).

2600243561 is an equidigital number, since it uses as much as digits as its factorization.

2600243561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70276890.

The product of its (nonzero) digits is 8640, while the sum is 29.

The square root of 2600243561 is about 50992.5833920973. The cubic root of 2600243561 is about 1375.1118033166. Note that the first 3 decimals are identical.

The spelling of 2600243561 in words is "two billion, six hundred million, two hundred forty-three thousand, five hundred sixty-one".