6539781600 has 432 divisors, whose sum is σ = 25533615744. Its totient is φ = 1561728000.

The previous prime is 6539781593. The next prime is 6539781601. The reversal of 6539781600 is 61879356.

It is a happy number.

6539781600 is a `hidden beast` number, since 6 + 5 + 39 + 7 + 8 + 1 + 600 = 666.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6539781601) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 5622619 + ... + 5623781.

It is an arithmetic number, because the mean of its divisors is an integer number (59105592).

Almost surely, 2^6539781600 is an apocalyptic number.

6539781600 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 6539781600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (12766807872).

6539781600 is an abundant number, since it is smaller than the sum of its proper divisors (18993834144).

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

6539781600 is a wasteful number, since it uses less digits than its factorization.

6539781600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1271 (or 1255 counting only the distinct ones).

The product of its (nonzero) digits is 272160, while the sum is 45.

The square root of 6539781600 is about 80868.9161544780. The cubic root of 6539781600 is about 1870.0551519856.

The spelling of 6539781600 in words is "six billion, five hundred thirty-nine million, seven hundred eighty-one thousand, six hundred".