7211128105 has 4 divisors (see below), whose sum is σ = 8653353732. Its totient is φ = 5768902480.

The previous prime is 7211128097. The next prime is 7211128123. The reversal of 7211128105 is 5018211127.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5018211127 = 29 ⋅173041763.

It can be written as a sum of positive squares in 2 ways, for example, as 5599828224 + 1611299881 = 74832^2 + 40141^2 .

It is not a de Polignac number, because 7211128105 - 2³ = 7211128097 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 721112806 + ... + 721112815.

It is an arithmetic number, because the mean of its divisors is an integer number (2163338433).

Almost surely, 2^7211128105 is an apocalyptic number.

It is an amenable number.

7211128105 is a deficient number, since it is larger than the sum of its proper divisors (1442225627).

7211128105 is a wasteful number, since it uses less digits than its factorization.

7211128105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1442225626.

The product of its (nonzero) digits is 1120, while the sum is 28.

The square root of 7211128105 is about 84918.3614125944. The cubic root of 7211128105 is about 1931.9730781705.

The spelling of 7211128105 in words is "seven billion, two hundred eleven million, one hundred twenty-eight thousand, one hundred five".