20115481 has 2 divisors, whose sum is σ = 20115482. Its totient is φ = 20115480.

The previous prime is 20115467. The next prime is 20115493. The reversal of 20115481 is 18451102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20115225 + 256 = 4485^2 + 16^2 .

It is a cyclic number.

It is not a de Polignac number, because 20115481 - 2⁵ = 20115449 is a prime.

It is a super-2 number, since 2×20115481² = 809265151722722, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20115451) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10057740 + 10057741.

It is an arithmetic number, because the mean of its divisors is an integer number (10057741).

Almost surely, 2^20115481 is an apocalyptic number.

It is an amenable number.

20115481 is a deficient number, since it is larger than the sum of its proper divisors (1).

20115481 is an equidigital number, since it uses as much as digits as its factorization.

20115481 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 320, while the sum is 22.

The square root of 20115481 is about 4485.0285394856. The cubic root of 20115481 is about 271.9631987768.

Adding to 20115481 its reverse (18451102), we get a palindrome (38566583).

The spelling of 20115481 in words is "twenty million, one hundred fifteen thousand, four hundred eighty-one".