8291981 has 2 divisors, whose sum is σ = 8291982. Its totient is φ = 8291980.

The previous prime is 8291953. The next prime is 8291989. The reversal of 8291981 is 1891928.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7155625 + 1136356 = 2675^2 + 1066^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-8291981 is a prime.

It is a super-2 number, since 2×8291981² = 137513897808722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8291989) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4145990 + 4145991.

It is an arithmetic number, because the mean of its divisors is an integer number (4145991).

Almost surely, 2^8291981 is an apocalyptic number.

It is an amenable number.

8291981 is a deficient number, since it is larger than the sum of its proper divisors (1).

8291981 is an equidigital number, since it uses as much as digits as its factorization.

8291981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10368, while the sum is 38.

The square root of 8291981 is about 2879.5800040978. The cubic root of 8291981 is about 202.4041592906.

The spelling of 8291981 in words is "eight million, two hundred ninety-one thousand, nine hundred eighty-one".