40540581 has 10 divisors (see below), whose sum is σ = 60560742. Its totient is φ = 27027000.

The previous prime is 40540553. The next prime is 40540583. The reversal of 40540581 is 18504504.

40540581 is a `hidden beast` number, since 40 + 5 + 40 + 581 = 666.

40540581 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 36796356 + 3744225 = 6066^2 + 1935^2 .

It is not a de Polignac number, because 40540581 - 2⁶ = 40540517 is a prime.

It is a super-2 number, since 2×40540581² = 3287077415635122, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40540583) 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 in 9 ways as a sum of consecutive naturals, for example, 250170 + ... + 250331.

Almost surely, 2^40540581 is an apocalyptic number.

It is an amenable number.

40540581 is a deficient number, since it is larger than the sum of its proper divisors (20020161).

40540581 is an equidigital number, since it uses as much as digits as its factorization.

40540581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 500513 (or 500504 counting only the distinct ones).

The product of its (nonzero) digits is 3200, while the sum is 27.

The square root of 40540581 is about 6367.1485768749. The cubic root of 40540581 is about 343.5289348445.

The spelling of 40540581 in words is "forty million, five hundred forty thousand, five hundred eighty-one".