6561671800 has 48 divisors (see below), whose sum is σ = 15483618360. Its totient is φ = 2585489280.

The previous prime is 6561671791. The next prime is 6561671801. The reversal of 6561671800 is 81761656.

It is a super-3 number, since 3×6561671800³ (a number of 30 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6561671801) 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, 231439 + ... + 258238.

Almost surely, 2^6561671800 is an apocalyptic number.

It is an amenable number.

6561671800 is an abundant number, since it is smaller than the sum of its proper divisors (8921946560).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

6561671800 is a wasteful number, since it uses less digits than its factorization.

6561671800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 489760 (or 489751 counting only the distinct ones).

The product of its (nonzero) digits is 60480, while the sum is 40.

The square root of 6561671800 is about 81004.1468074320. The cubic root of 6561671800 is about 1872.1393343279.

The spelling of 6561671800 in words is "six billion, five hundred sixty-one million, six hundred seventy-one thousand, eight hundred".