140505581 has 2 divisors, whose sum is σ = 140505582. Its totient is φ = 140505580.

The previous prime is 140505577. The next prime is 140505587. The reversal of 140505581 is 185505041.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 135256900 + 5248681 = 11630^2 + 2291^2 .

It is an emirp because it is prime and its reverse (185505041) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 140505581 - 2² = 140505577 is a prime.

It is a super-2 number, since 2×140505581² = 39483636584295122, which 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 (140505587) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 70252790 + 70252791.

It is an arithmetic number, because the mean of its divisors is an integer number (70252791).

Almost surely, 2^140505581 is an apocalyptic number.

It is an amenable number.

140505581 is a deficient number, since it is larger than the sum of its proper divisors (1).

140505581 is an equidigital number, since it uses as much as digits as its factorization.

140505581 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4000, while the sum is 29.

The square root of 140505581 is about 11853.5050090680. The cubic root of 140505581 is about 519.8737131688.

The spelling of 140505581 in words is "one hundred forty million, five hundred five thousand, five hundred eighty-one".