6543338261 has 4 divisors (see below), whose sum is σ = 6682558272. Its totient is φ = 6404118252.

The previous prime is 6543338239. The next prime is 6543338309. The reversal of 6543338261 is 1628333456.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 6543338261 - 2¹⁸ = 6543076117 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6543338761) 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, 69609935 + ... + 69610028.

It is an arithmetic number, because the mean of its divisors is an integer number (1670639568).

Almost surely, 2^6543338261 is an apocalyptic number.

It is an amenable number.

6543338261 is a deficient number, since it is larger than the sum of its proper divisors (139220011).

6543338261 is a wasteful number, since it uses less digits than its factorization.

6543338261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 139220010.

The product of its digits is 311040, while the sum is 41.

The square root of 6543338261 is about 80890.9034502644. The cubic root of 6543338261 is about 1870.3941004528.

The spelling of 6543338261 in words is "six billion, five hundred forty-three million, three hundred thirty-eight thousand, two hundred sixty-one".