6556525021 has 4 divisors (see below), whose sum is σ = 6569110044. Its totient is φ = 6543940000.

The previous prime is 6556525009. The next prime is 6556525057. The reversal of 6556525021 is 1205256556.

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 3582022500 + 2974502521 = 59850^2 + 54539^2 .

It is a cyclic number.

It is not a de Polignac number, because 6556525021 - 2²⁵ = 6522970589 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 (6556525081) 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, 6291730 + ... + 6292771.

It is an arithmetic number, because the mean of its divisors is an integer number (1642277511).

Almost surely, 2^6556525021 is an apocalyptic number.

It is an amenable number.

6556525021 is a deficient number, since it is larger than the sum of its proper divisors (12585023).

6556525021 is a wasteful number, since it uses less digits than its factorization.

6556525021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12585022.

The product of its (nonzero) digits is 90000, while the sum is 37.

The square root of 6556525021 is about 80972.3719610584. The cubic root of 6556525021 is about 1871.6497229369.

The spelling of 6556525021 in words is "six billion, five hundred fifty-six million, five hundred twenty-five thousand, twenty-one".