20842015081 has 2 divisors, whose sum is σ = 20842015082. Its totient is φ = 20842015080.

The previous prime is 20842015069. The next prime is 20842015091. The reversal of 20842015081 is 18051024802.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17393389456 + 3448625625 = 131884^2 + 58725^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20842015081 is a prime.

It is a super-2 number, since 2×20842015081² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20842015031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10421007540 + 10421007541.

It is an arithmetic number, because the mean of its divisors is an integer number (10421007541).

Almost surely, 2^20842015081 is an apocalyptic number.

It is an amenable number.

20842015081 is a deficient number, since it is larger than the sum of its proper divisors (1).

20842015081 is an equidigital number, since it uses as much as digits as its factorization.

20842015081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5120, while the sum is 31.

Adding to 20842015081 its reverse (18051024802), we get a palindrome (38893039883).

The spelling of 20842015081 in words is "twenty billion, eight hundred forty-two million, fifteen thousand, eighty-one".