6554543721 has 32 divisors (see below), whose sum is σ = 9880790400. Its totient is φ = 3828410880.

The previous prime is 6554543687. The next prime is 6554543729. The reversal of 6554543721 is 1273454556.

It is not a de Polignac number, because 6554543721 - 2¹¹ = 6554541673 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (6554543729) 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 31 ways as a sum of consecutive naturals, for example, 538515 + ... + 550551.

It is an arithmetic number, because the mean of its divisors is an integer number (308774700).

Almost surely, 2^6554543721 is an apocalyptic number.

It is an amenable number.

6554543721 is a deficient number, since it is larger than the sum of its proper divisors (3326246679).

6554543721 is a wasteful number, since it uses less digits than its factorization.

6554543721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12649.

The product of its digits is 504000, while the sum is 42.

The square root of 6554543721 is about 80960.1366167326. The cubic root of 6554543721 is about 1871.4611742173.

The spelling of 6554543721 in words is "six billion, five hundred fifty-four million, five hundred forty-three thousand, seven hundred twenty-one".