6564994121 has 16 divisors (see below), whose sum is σ = 7905091584. Its totient is φ = 5330209104.

The previous prime is 6564994099. The next prime is 6564994123. The reversal of 6564994121 is 1214994656.

It is a cyclic number.

It is not a de Polignac number, because 6564994121 - 2²⁶ = 6497885257 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (6564994123) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 181361 + ... + 214526.

It is an arithmetic number, because the mean of its divisors is an integer number (494068224).

Almost surely, 2^6564994121 is an apocalyptic number.

It is an amenable number.

6564994121 is a deficient number, since it is larger than the sum of its proper divisors (1340097463).

6564994121 is a wasteful number, since it uses less digits than its factorization.

6564994121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 396020.

The product of its digits is 466560, while the sum is 47.

The square root of 6564994121 is about 81024.6513167443. The cubic root of 6564994121 is about 1872.4552496698.

The spelling of 6564994121 in words is "six billion, five hundred sixty-four million, nine hundred ninety-four thousand, one hundred twenty-one".