7811140121 has 4 divisors (see below), whose sum is σ = 7888478244. Its totient is φ = 7733802000.

The previous prime is 7811140067. The next prime is 7811140123. The reversal of 7811140121 is 1210411187.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 7388262025 + 422878096 = 85955^2 + 20564^2 .

It is a cyclic number.

It is not a de Polignac number, because 7811140121 - 2¹⁰ = 7811139097 is a prime.

It is a super-2 number, since 2×7811140121² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (7811140123) 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, 38668910 + ... + 38669111.

It is an arithmetic number, because the mean of its divisors is an integer number (1972119561).

Almost surely, 2^7811140121 is an apocalyptic number.

It is an amenable number.

7811140121 is a deficient number, since it is larger than the sum of its proper divisors (77338123).

7811140121 is a wasteful number, since it uses less digits than its factorization.

7811140121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77338122.

The product of its (nonzero) digits is 448, while the sum is 26.

The square root of 7811140121 is about 88380.6546762356. The cubic root of 7811140121 is about 1984.1361790340.

The spelling of 7811140121 in words is "seven billion, eight hundred eleven million, one hundred forty thousand, one hundred twenty-one".