6561324004 has 27 divisors (see below), whose sum is σ = 11626121563. Its totient is φ = 3240080000.

The previous prime is 6561323999. The next prime is 6561324041. The reversal of 6561324004 is 4004231656.

The square root of 6561324004 is 81002.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 5991069604 + 570254400 = 77402^2 + 23880^2 .

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 16362204 + ... + 16362604.

Almost surely, 2^6561324004 is an apocalyptic number.

6561324004 is the 81002-nd square number.

It is an amenable number.

6561324004 is a deficient number, since it is larger than the sum of its proper divisors (5064797559).

6561324004 is an equidigital number, since it uses as much as digits as its factorization.

6561324004 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1008 (or 504 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 31.

The cubic root of 6561324004 is about 1872.1062566765.

The spelling of 6561324004 in words is "six billion, five hundred sixty-one million, three hundred twenty-four thousand, four".