20116531 has 2 divisors, whose sum is σ = 20116532. Its totient is φ = 20116530.

The previous prime is 20116487. The next prime is 20116543. The reversal of 20116531 is 13561102.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20116531 - 2²³ = 11727923 is a prime.

It is a super-2 number, since 2×20116531² = 809349638947922, which contains 22 as substring.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 20116499 and 20116508.

It is not a weakly prime, because it can be changed into another prime (20114531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10058265 + 10058266.

It is an arithmetic number, because the mean of its divisors is an integer number (10058266).

Almost surely, 2^20116531 is an apocalyptic number.

20116531 is the 2590-th hex number.

20116531 is a deficient number, since it is larger than the sum of its proper divisors (1).

20116531 is an equidigital number, since it uses as much as digits as its factorization.

20116531 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 180, while the sum is 19.

The square root of 20116531 is about 4485.1455940694. The cubic root of 20116531 is about 271.9679307275.

Adding to 20116531 its reverse (13561102), we get a palindrome (33677633).

The spelling of 20116531 in words is "twenty million, one hundred sixteen thousand, five hundred thirty-one".