945571981 has 2 divisors, whose sum is σ = 945571982. Its totient is φ = 945571980.

The previous prime is 945571927. The next prime is 945572059. The reversal of 945571981 is 189175549.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 670343881 + 275228100 = 25891^2 + 16590^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-945571981 is a prime.

It is a super-2 number, since 2×945571981² = 1788212742504528722, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (945571381) 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, 472785990 + 472785991.

It is an arithmetic number, because the mean of its divisors is an integer number (472785991).

Almost surely, 2^945571981 is an apocalyptic number.

It is an amenable number.

945571981 is a deficient number, since it is larger than the sum of its proper divisors (1).

945571981 is an equidigital number, since it uses as much as digits as its factorization.

945571981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 453600, while the sum is 49.

The square root of 945571981 is about 30750.1541622152. The cubic root of 945571981 is about 981.5178412493.

The spelling of 945571981 in words is "nine hundred forty-five million, five hundred seventy-one thousand, nine hundred eighty-one".