7881331891 has 2 divisors, whose sum is σ = 7881331892. Its totient is φ = 7881331890.

The previous prime is 7881331883. The next prime is 7881331933. The reversal of 7881331891 is 1981331887.

It is a weak prime.

It is an emirp because it is prime and its reverse (1981331887) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 7881331891 - 2³ = 7881331883 is a prime.

It is not a weakly prime, because it can be changed into another prime (7881331091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3940665945 + 3940665946.

It is an arithmetic number, because the mean of its divisors is an integer number (3940665946).

Almost surely, 2^7881331891 is an apocalyptic number.

7881331891 is a deficient number, since it is larger than the sum of its proper divisors (1).

7881331891 is an equidigital number, since it uses as much as digits as its factorization.

7881331891 is an evil number, because the sum of its binary digits is even.

The product of its digits is 290304, while the sum is 49.

The square root of 7881331891 is about 88776.8657421515. The cubic root of 7881331891 is about 1990.0616876915.

The spelling of 7881331891 in words is "seven billion, eight hundred eighty-one million, three hundred thirty-one thousand, eight hundred ninety-one".