6561737500 has 36 divisors (see below), whose sum is σ = 14352909480. Its totient is φ = 2624690000.

The previous prime is 6561737489. The next prime is 6561737549. The reversal of 6561737500 is 57371656.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 249970 + ... + 274969.

It is an arithmetic number, because the mean of its divisors is an integer number (398691930).

Almost surely, 2^6561737500 is an apocalyptic number.

It is an amenable number.

6561737500 is an abundant number, since it is smaller than the sum of its proper divisors (7791171980).

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

6561737500 is an equidigital number, since it uses as much as digits as its factorization.

6561737500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 524968 (or 524946 counting only the distinct ones).

The product of its (nonzero) digits is 132300, while the sum is 40.

The square root of 6561737500 is about 81004.5523412110. The cubic root of 6561737500 is about 1872.1455826920.

The spelling of 6561737500 in words is "six billion, five hundred sixty-one million, seven hundred thirty-seven thousand, five hundred".