8121956064 has 48 divisors (see below), whose sum is σ = 21326230800. Its totient is φ = 2706544640.

The previous prime is 8121956039. The next prime is 8121956069. The reversal of 8121956064 is 4606591218.

It is a tau number, because it is divible by the number of its divisors (48).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8121956069) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 397162 + ... + 417110.

It is an arithmetic number, because the mean of its divisors is an integer number (444296475).

Almost surely, 2^8121956064 is an apocalyptic number.

It is an amenable number.

8121956064 is an abundant number, since it is smaller than the sum of its proper divisors (13204274736).

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

8121956064 is a wasteful number, since it uses less digits than its factorization.

8121956064 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24203 (or 24195 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 42.

The square root of 8121956064 is about 90121.8955859230. The cubic root of 8121956064 is about 2010.1117949750. Note that the first 3 decimals are identical.

The spelling of 8121956064 in words is "eight billion, one hundred twenty-one million, nine hundred fifty-six thousand, sixty-four".