6541121565 has 48 divisors (see below), whose sum is σ = 12538169280. Its totient is φ = 3127991040.

The previous prime is 6541121563. The next prime is 6541121579. The reversal of 6541121565 is 5651211456.

6541121565 is a `hidden beast` number, since 65 + 4 + 11 + 21 + 565 = 666.

It is not a de Polignac number, because 6541121565 - 2¹ = 6541121563 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6541121563) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 54375 + ... + 126644.

It is an arithmetic number, because the mean of its divisors is an integer number (261211860).

Almost surely, 2^6541121565 is an apocalyptic number.

It is an amenable number.

6541121565 is a deficient number, since it is larger than the sum of its proper divisors (5997047715).

6541121565 is a wasteful number, since it uses less digits than its factorization.

6541121565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 181114 (or 181111 counting only the distinct ones).

The product of its digits is 36000, while the sum is 36.

The square root of 6541121565 is about 80877.2005264772. The cubic root of 6541121565 is about 1870.1828645752.

The spelling of 6541121565 in words is "six billion, five hundred forty-one million, one hundred twenty-one thousand, five hundred sixty-five".