7917881 has 2 divisors, whose sum is σ = 7917882. Its totient is φ = 7917880.

The previous prime is 7917863. The next prime is 7917883. The reversal of 7917881 is 1887197.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7203856 + 714025 = 2684^2 + 845^2 .

It is a cyclic number.

It is not a de Polignac number, because 7917881 - 2⁶ = 7917817 is a prime.

It is a super-2 number, since 2×7917881² = 125385679060322, which contains 22 as substring.

Together with 7917883, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (7917883) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3958940 + 3958941.

It is an arithmetic number, because the mean of its divisors is an integer number (3958941).

Almost surely, 2^7917881 is an apocalyptic number.

It is an amenable number.

7917881 is a deficient number, since it is larger than the sum of its proper divisors (1).

7917881 is an equidigital number, since it uses as much as digits as its factorization.

7917881 is an evil number, because the sum of its binary digits is even.

The product of its digits is 28224, while the sum is 41.

The square root of 7917881 is about 2813.8729537774. The cubic root of 7917881 is about 199.3133200515.

The spelling of 7917881 in words is "seven million, nine hundred seventeen thousand, eight hundred eighty-one".