6521000643 has 12 divisors (see below), whose sum is σ = 9453983968. Its totient is φ = 4331290320.

The previous prime is 6521000599. The next prime is 6521000693. The reversal of 6521000643 is 3460001256.

6521000643 is a `hidden beast` number, since 6 + 5 + 2 + 10 + 0 + 0 + 643 = 666.

It is not a de Polignac number, because 6521000643 - 2⁶ = 6521000579 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6521000693) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1334380 + ... + 1339257.

Almost surely, 2^6521000643 is an apocalyptic number.

6521000643 is a deficient number, since it is larger than the sum of its proper divisors (2932983325).

6521000643 is a wasteful number, since it uses less digits than its factorization.

6521000643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2673914 (or 2673911 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 27.

The square root of 6521000643 is about 80752.7129141802. The cubic root of 6521000643 is about 1868.2632929766.

Adding to 6521000643 its reverse (3460001256), we get a palindrome (9981001899).

The spelling of 6521000643 in words is "six billion, five hundred twenty-one million, six hundred forty-three", and thus it is an aban number.