6643804487 has 4 divisors (see below), whose sum is σ = 6742965816. Its totient is φ = 6544643160.

The previous prime is 6643804477. The next prime is 6643804501. The reversal of 6643804487 is 7844083466.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7844083466 = 2 ⋅3922041733.

It is a cyclic number.

It is not a de Polignac number, because 6643804487 - 2⁸ = 6643804231 is a prime.

It is a super-2 number, since 2×6643804487² = 88280276122962666338, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6643804477) 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, 49580564 + ... + 49580697.

It is an arithmetic number, because the mean of its divisors is an integer number (1685741454).

Almost surely, 2^6643804487 is an apocalyptic number.

6643804487 is a gapful number since it is divisible by the number (67) formed by its first and last digit.

6643804487 is a deficient number, since it is larger than the sum of its proper divisors (99161329).

6643804487 is an equidigital number, since it uses as much as digits as its factorization.

6643804487 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 99161328.

The product of its (nonzero) digits is 3096576, while the sum is 50.

The square root of 6643804487 is about 81509.5361721560. The cubic root of 6643804487 is about 1879.9181802893.

The spelling of 6643804487 in words is "six billion, six hundred forty-three million, eight hundred four thousand, four hundred eighty-seven".