20140185581 has 2 divisors, whose sum is σ = 20140185582. Its totient is φ = 20140185580.

The previous prime is 20140185551. The next prime is 20140185607. The reversal of 20140185581 is 18558104102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10596849481 + 9543336100 = 102941^2 + 97690^2 .

It is a cyclic number.

It is not a de Polignac number, because 20140185581 - 2¹⁰ = 20140184557 is a prime.

It is a super-2 number, since 2×20140185581² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20140185521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10070092790 + 10070092791.

It is an arithmetic number, because the mean of its divisors is an integer number (10070092791).

Almost surely, 2^20140185581 is an apocalyptic number.

It is an amenable number.

20140185581 is a deficient number, since it is larger than the sum of its proper divisors (1).

20140185581 is an equidigital number, since it uses as much as digits as its factorization.

20140185581 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12800, while the sum is 35.

Adding to 20140185581 its reverse (18558104102), we get a palindrome (38698289683).

The spelling of 20140185581 in words is "twenty billion, one hundred forty million, one hundred eighty-five thousand, five hundred eighty-one".