6539641920 has 840 divisors, whose sum is σ = 28589996160. Its totient is φ = 1410877440.

The previous prime is 6539641919. The next prime is 6539641967. The reversal of 6539641920 is 291469356.

It is a tau number, because it is divible by the number of its divisors (840).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 24131385 + ... + 24131655.

Almost surely, 2^6539641920 is an apocalyptic number.

6539641920 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6539641920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (14294998080).

6539641920 is an abundant number, since it is smaller than the sum of its proper divisors (22050354240).

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

6539641920 is a wasteful number, since it uses less digits than its factorization.

6539641920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 333 (or 307 counting only the distinct ones).

The product of its (nonzero) digits is 349920, while the sum is 45.

The square root of 6539641920 is about 80868.0525300319. The cubic root of 6539641920 is about 1870.0418380261.

The spelling of 6539641920 in words is "six billion, five hundred thirty-nine million, six hundred forty-one thousand, nine hundred twenty".