6555518640 has 360 divisors, whose sum is σ = 24729292224. Its totient is φ = 1554432000.

The previous prime is 6555518591. The next prime is 6555518647. The reversal of 6555518640 is 468155556.

6555518640 is a `hidden beast` number, since 6 + 55 + 551 + 8 + 6 + 40 = 666.

It is a tau number, because it is divible by the number of its divisors (360).

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

It is not an unprimeable number, because it can be changed into a prime (6555518647) 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, 4093840 + ... + 4095440.

Almost surely, 2^6555518640 is an apocalyptic number.

6555518640 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 6555518640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (12364646112).

6555518640 is an abundant number, since it is smaller than the sum of its proper divisors (18173773584).

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

6555518640 is a wasteful number, since it uses less digits than its factorization.

6555518640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1689 (or 1669 counting only the distinct ones).

The product of its (nonzero) digits is 720000, while the sum is 45.

The square root of 6555518640 is about 80966.1573745475. The cubic root of 6555518640 is about 1871.5539562976.

The spelling of 6555518640 in words is "six billion, five hundred fifty-five million, five hundred eighteen thousand, six hundred forty".