6543766440 has 512 divisors, whose sum is σ = 24182784000. Its totient is φ = 1587237120.

The previous prime is 6543766433. The next prime is 6543766487. The reversal of 6543766440 is 446673456.

It is a happy number.

6543766440 is a `hidden beast` number, since 6 + 543 + 7 + 6 + 64 + 40 = 666.

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

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 51525657 + ... + 51525783.

It is an arithmetic number, because the mean of its divisors is an integer number (47232000).

Almost surely, 2^6543766440 is an apocalyptic number.

6543766440 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 6543766440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (12091392000).

6543766440 is an abundant number, since it is smaller than the sum of its proper divisors (17639017560).

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

6543766440 is a wasteful number, since it uses less digits than its factorization.

6543766440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 209 (or 187 counting only the distinct ones).

The product of its (nonzero) digits is 1451520, while the sum is 45.

The square root of 6543766440 is about 80893.5500519046. The cubic root of 6543766440 is about 1870.4348974678.

The spelling of 6543766440 in words is "six billion, five hundred forty-three million, seven hundred sixty-six thousand, four hundred forty".