7881961 has 2 divisors, whose sum is σ = 7881962. Its totient is φ = 7881960.

The previous prime is 7881959. The next prime is 7881971. The reversal of 7881961 is 1691887.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5382400 + 2499561 = 2320^2 + 1581^2 .

It is a cyclic number.

It is not a de Polignac number, because 7881961 - 2¹ = 7881959 is a prime.

Together with 7881959, it forms a pair of twin primes.

It is a zygodrome in base 3.

It is not a weakly prime, because it can be changed into another prime (7881901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3940980 + 3940981.

It is an arithmetic number, because the mean of its divisors is an integer number (3940981).

Almost surely, 2^7881961 is an apocalyptic number.

It is an amenable number.

7881961 is a deficient number, since it is larger than the sum of its proper divisors (1).

7881961 is an equidigital number, since it uses as much as digits as its factorization.

7881961 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 24192, while the sum is 40.

The square root of 7881961 is about 2807.4830364581. The cubic root of 7881961 is about 199.0114636966.

The spelling of 7881961 in words is "seven million, eight hundred eighty-one thousand, nine hundred sixty-one".