7891121131 has 2 divisors, whose sum is σ = 7891121132. Its totient is φ = 7891121130.

The previous prime is 7891121113. The next prime is 7891121143. The reversal of 7891121131 is 1311211987.

Together with previous prime (7891121113) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is an emirp because it is prime and its reverse (1311211987) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 7891121131 - 2¹⁹ = 7890596843 is a prime.

It is a super-2 number, since 2×7891121131² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (7891127131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3945560565 + 3945560566.

It is an arithmetic number, because the mean of its divisors is an integer number (3945560566).

Almost surely, 2^7891121131 is an apocalyptic number.

7891121131 is a deficient number, since it is larger than the sum of its proper divisors (1).

7891121131 is an equidigital number, since it uses as much as digits as its factorization.

7891121131 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3024, while the sum is 34.

The square root of 7891121131 is about 88831.9825907314. The cubic root of 7891121131 is about 1990.8852850047.

The spelling of 7891121131 in words is "seven billion, eight hundred ninety-one million, one hundred twenty-one thousand, one hundred thirty-one".