6561213736 has 64 divisors (see below), whose sum is σ = 15832719360. Its totient is φ = 2473848000.

The previous prime is 6561213713. The next prime is 6561213773. The reversal of 6561213736 is 6373121656.

It is a hoax number, since the sum of its digits (40) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 152700 + ... + 190891.

It is an arithmetic number, because the mean of its divisors is an integer number (247386240).

Almost surely, 2^6561213736 is an apocalyptic number.

It is an amenable number.

6561213736 is an abundant number, since it is smaller than the sum of its proper divisors (9271505624).

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

6561213736 is a wasteful number, since it uses less digits than its factorization.

6561213736 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 343646 (or 343642 counting only the distinct ones).

The product of its digits is 136080, while the sum is 40.

The square root of 6561213736 is about 81001.3193472798. The cubic root of 6561213736 is about 1872.0957692318.

The spelling of 6561213736 in words is "six billion, five hundred sixty-one million, two hundred thirteen thousand, seven hundred thirty-six".