6390545521 has 4 divisors (see below), whose sum is σ = 6391226944. Its totient is φ = 6389864100.

The previous prime is 6390545509. The next prime is 6390545527. The reversal of 6390545521 is 1255450936.

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 6390545521 - 2⁵ = 6390545489 is a prime.

It is a super-2 number, since 2×6390545521² = 81678144111946322882, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6390545527) 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, 326445 + ... + 345466.

It is an arithmetic number, because the mean of its divisors is an integer number (1597806736).

Almost surely, 2^6390545521 is an apocalyptic number.

It is an amenable number.

6390545521 is a deficient number, since it is larger than the sum of its proper divisors (681423).

6390545521 is an equidigital number, since it uses as much as digits as its factorization.

6390545521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 681422.

The product of its (nonzero) digits is 162000, while the sum is 40.

The square root of 6390545521 is about 79940.8876670756. The cubic root of 6390545521 is about 1855.7208369617.

The spelling of 6390545521 in words is "six billion, three hundred ninety million, five hundred forty-five thousand, five hundred twenty-one".