40545606581 has 2 divisors, whose sum is σ = 40545606582. Its totient is φ = 40545606580.

The previous prime is 40545606503. The next prime is 40545606641. The reversal of 40545606581 is 18560654504.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 27040842481 + 13504764100 = 164441^2 + 116210^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-40545606581 is a prime.

It is a super-2 number, since 2×40545606581² (a number of 22 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (40545606481) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20272803290 + 20272803291.

It is an arithmetic number, because the mean of its divisors is an integer number (20272803291).

Almost surely, 2^40545606581 is an apocalyptic number.

It is an amenable number.

40545606581 is a deficient number, since it is larger than the sum of its proper divisors (1).

40545606581 is an equidigital number, since it uses as much as digits as its factorization.

40545606581 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 576000, while the sum is 44.

The spelling of 40545606581 in words is "forty billion, five hundred forty-five million, six hundred six thousand, five hundred eighty-one".