6620915880 has 288 divisors, whose sum is σ = 23224841640. Its totient is φ = 1630126080.

The previous prime is 6620915849. The next prime is 6620915887. The reversal of 6620915880 is 885190266.

6620915880 is a `hidden beast` number, since 6 + 62 + 0 + 9 + 1 + 588 + 0 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 6399680004 + 221235876 = 79998^2 + 14874^2 .

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 (6620915887) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 27472560 + ... + 27472800.

Almost surely, 2^6620915880 is an apocalyptic number.

6620915880 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 6620915880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (11612420820).

6620915880 is an abundant number, since it is smaller than the sum of its proper divisors (16603925760).

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

6620915880 is a wasteful number, since it uses less digits than its factorization.

6620915880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 409 (or 335 counting only the distinct ones).

The product of its (nonzero) digits is 207360, while the sum is 45.

The square root of 6620915880 is about 81369.0105629901. The cubic root of 6620915880 is about 1877.7568576060.

The spelling of 6620915880 in words is "six billion, six hundred twenty million, nine hundred fifteen thousand, eight hundred eighty".