40945981 has 2 divisors, whose sum is σ = 40945982. Its totient is φ = 40945980.

The previous prime is 40945973. The next prime is 40945991. The reversal of 40945981 is 18954904.

40945981 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 26429881 + 14516100 = 5141^2 + 3810^2 .

It is a cyclic number.

It is not a de Polignac number, because 40945981 - 2³ = 40945973 is a prime.

It is a super-2 number, since 2×40945981² = 3353146720104722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (40945901) 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, 20472990 + 20472991.

It is an arithmetic number, because the mean of its divisors is an integer number (20472991).

Almost surely, 2^40945981 is an apocalyptic number.

It is an amenable number.

40945981 is a deficient number, since it is larger than the sum of its proper divisors (1).

40945981 is an equidigital number, since it uses as much as digits as its factorization.

40945981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 51840, while the sum is 40.

The square root of 40945981 is about 6398.9046718950. The cubic root of 40945981 is about 344.6702190687.

The spelling of 40945981 in words is "forty million, nine hundred forty-five thousand, nine hundred eighty-one".