40918981 has 2 divisors, whose sum is σ = 40918982. Its totient is φ = 40918980.

The previous prime is 40918973. The next prime is 40918987. The reversal of 40918981 is 18981904.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 29528356 + 11390625 = 5434^2 + 3375^2 .

It is a cyclic number.

It is not a de Polignac number, because 40918981 - 2³ = 40918973 is a prime.

It is a super-2 number, since 2×40918981² = 3348726012156722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (40918987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20459490 + 20459491.

It is an arithmetic number, because the mean of its divisors is an integer number (20459491).

Almost surely, 2^40918981 is an apocalyptic number.

It is an amenable number.

40918981 is a deficient number, since it is larger than the sum of its proper divisors (1).

40918981 is an equidigital number, since it uses as much as digits as its factorization.

40918981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 20736, while the sum is 40.

The square root of 40918981 is about 6396.7945879167. The cubic root of 40918981 is about 344.5944432788.

The spelling of 40918981 in words is "forty million, nine hundred eighteen thousand, nine hundred eighty-one".