40057981 has 2 divisors, whose sum is σ = 40057982. Its totient is φ = 40057980.

The previous prime is 40057957. The next prime is 40057999. The reversal of 40057981 is 18975004.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 33120025 + 6937956 = 5755^2 + 2634^2 .

It is a cyclic number.

It is not a de Polignac number, because 40057981 - 2⁹ = 40057469 is a prime.

It is a super-2 number, since 2×40057981² = 3209283683592722, which contains 22 as substring.

It is equal to p_2436928 and since 40057981 and 2436928 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (40057931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20028990 + 20028991.

It is an arithmetic number, because the mean of its divisors is an integer number (20028991).

Almost surely, 2^40057981 is an apocalyptic number.

It is an amenable number.

40057981 is a deficient number, since it is larger than the sum of its proper divisors (1).

40057981 is an equidigital number, since it uses as much as digits as its factorization.

40057981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10080, while the sum is 34.

The square root of 40057981 is about 6329.1374609816. The cubic root of 40057981 is about 342.1603530836.

The spelling of 40057981 in words is "forty million, fifty-seven thousand, nine hundred eighty-one".