6540644620 has 24 divisors (see below), whose sum is σ = 13786049088. Its totient is φ = 2606601600.

The previous prime is 6540644599. The next prime is 6540644629. The reversal of 6540644620 is 264460456.

It is a self number, because there is not a number n which added to its sum of digits gives 6540644620.

It is not an unprimeable number, because it can be changed into a prime (6540644629) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 597961 + ... + 608800.

It is an arithmetic number, because the mean of its divisors is an integer number (574418712).

Almost surely, 2^6540644620 is an apocalyptic number.

It is an amenable number.

6540644620 is an abundant number, since it is smaller than the sum of its proper divisors (7245404468).

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

6540644620 is a wasteful number, since it uses less digits than its factorization.

6540644620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1207041 (or 1207039 counting only the distinct ones).

The product of its (nonzero) digits is 138240, while the sum is 37.

The square root of 6540644620 is about 80874.2518976219. The cubic root of 6540644620 is about 1870.1374087596.

The spelling of 6540644620 in words is "six billion, five hundred forty million, six hundred forty-four thousand, six hundred twenty".