40991281 has 2 divisors, whose sum is σ = 40991282. Its totient is φ = 40991280.

The previous prime is 40991273. The next prime is 40991299. The reversal of 40991281 is 18219904.

40991281 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., 29322225 + 11669056 = 5415^2 + 3416^2 .

It is a cyclic number.

It is not a de Polignac number, because 40991281 - 2³ = 40991273 is a prime.

It is a super-2 number, since 2×40991281² = 3360570236041922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (40991201) 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, 20495640 + 20495641.

It is an arithmetic number, because the mean of its divisors is an integer number (20495641).

Almost surely, 2^40991281 is an apocalyptic number.

It is an amenable number.

40991281 is a deficient number, since it is larger than the sum of its proper divisors (1).

40991281 is an equidigital number, since it uses as much as digits as its factorization.

40991281 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5184, while the sum is 34.

The square root of 40991281 is about 6402.4433617175. The cubic root of 40991281 is about 344.7972792110.

The spelling of 40991281 in words is "forty million, nine hundred ninety-one thousand, two hundred eighty-one".