6121664064 has 84 divisors (see below), whose sum is σ = 17594304156. Its totient is φ = 2035012608.

The previous prime is 6121664063. The next prime is 6121664077. The reversal of 6121664064 is 4604661216.

6121664064 is a `hidden beast` number, since 6 + 1 + 2 + 1 + 6 + 640 + 6 + 4 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 3295678464 + 2825985600 = 57408^2 + 53160^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (6121664063) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 200602 + ... + 229094.

Almost surely, 2^6121664064 is an apocalyptic number.

6121664064 is a gapful number since it is divisible by the number (64) 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 6121664064, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (8797152078).

6121664064 is an abundant number, since it is smaller than the sum of its proper divisors (11472640092).

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

6121664064 is a wasteful number, since it uses less digits than its factorization.

6121664064 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28884 (or 28871 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 36.

The square root of 6121664064 is about 78241.0637964490. The cubic root of 6121664064 is about 1829.3206257186.

The spelling of 6121664064 in words is "six billion, one hundred twenty-one million, six hundred sixty-four thousand, sixty-four".