7945981 has 2 divisors, whose sum is σ = 7945982. Its totient is φ = 7945980.

The previous prime is 7945979. The next prime is 7946023. The reversal of 7945981 is 1895497.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7812025 + 133956 = 2795^2 + 366^2 .

It is a cyclic number.

It is not a de Polignac number, because 7945981 - 2¹ = 7945979 is a prime.

It is a super-2 number, since 2×7945981² = 126277228104722, which contains 22 as substring.

Together with 7945979, it forms a pair of twin primes.

7945981 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7945081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3972990 + 3972991.

It is an arithmetic number, because the mean of its divisors is an integer number (3972991).

Almost surely, 2^7945981 is an apocalyptic number.

It is an amenable number.

7945981 is a deficient number, since it is larger than the sum of its proper divisors (1).

7945981 is an equidigital number, since it uses as much as digits as its factorization.

7945981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 90720, while the sum is 43.

The square root of 7945981 is about 2818.8616496735. The cubic root of 7945981 is about 199.5488246360.

The spelling of 7945981 in words is "seven million, nine hundred forty-five thousand, nine hundred eighty-one".