7128121351 has 4 divisors (see below), whose sum is σ = 7676438392. Its totient is φ = 6579804312.

The previous prime is 7128121331. The next prime is 7128121391. The reversal of 7128121351 is 1531218217.

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

It is a cyclic number.

It is not a de Polignac number, because 7128121351 - 2¹¹ = 7128119303 is a prime.

It is a super-2 number, since 2×7128121351² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7128121321) 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, 274158501 + ... + 274158526.

It is an arithmetic number, because the mean of its divisors is an integer number (1919109598).

Almost surely, 2^7128121351 is an apocalyptic number.

7128121351 is a deficient number, since it is larger than the sum of its proper divisors (548317041).

7128121351 is a wasteful number, since it uses less digits than its factorization.

7128121351 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 548317040.

The product of its digits is 3360, while the sum is 31.

The square root of 7128121351 is about 84428.2023437666. The cubic root of 7128121351 is about 1924.5315193019.

Adding to 7128121351 its reverse (1531218217), we get a palindrome (8659339568).

The spelling of 7128121351 in words is "seven billion, one hundred twenty-eight million, one hundred twenty-one thousand, three hundred fifty-one".