7791447121 has 4 divisors (see below), whose sum is σ = 7830997812. Its totient is φ = 7751896432.

The previous prime is 7791447091. The next prime is 7791447143. The reversal of 7791447121 is 1217441977.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1217441977 = 1399 ⋅870223.

It can be written as a sum of positive squares in 2 ways, for example, as 4877066896 + 2914380225 = 69836^2 + 53985^2 .

It is a cyclic number.

It is not a de Polignac number, because 7791447121 - 2¹⁵ = 7791414353 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7791447151) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19775050 + ... + 19775443.

It is an arithmetic number, because the mean of its divisors is an integer number (1957749453).

Almost surely, 2^7791447121 is an apocalyptic number.

It is an amenable number.

7791447121 is a deficient number, since it is larger than the sum of its proper divisors (39550691).

7791447121 is a wasteful number, since it uses less digits than its factorization.

7791447121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39550690.

The product of its digits is 98784, while the sum is 43.

The square root of 7791447121 is about 88269.1742399350. The cubic root of 7791447121 is about 1982.4673455500.

The spelling of 7791447121 in words is "seven billion, seven hundred ninety-one million, four hundred forty-seven thousand, one hundred twenty-one".