20616161 has 2 divisors, whose sum is σ = 20616162. Its totient is φ = 20616160.

The previous prime is 20616143. The next prime is 20616179. The reversal of 20616161 is 16161602.

It is a balanced prime because it is at equal distance from previous prime (20616143) and next prime (20616179).

It can be written as a sum of positive squares in only one way, i.e., 20430400 + 185761 = 4520^2 + 431^2 .

It is a cyclic number.

It is not a de Polignac number, because 20616161 - 2²² = 16421857 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (20616191) 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, 10308080 + 10308081.

It is an arithmetic number, because the mean of its divisors is an integer number (10308081).

Almost surely, 2^20616161 is an apocalyptic number.

It is an amenable number.

20616161 is a deficient number, since it is larger than the sum of its proper divisors (1).

20616161 is an equidigital number, since it uses as much as digits as its factorization.

20616161 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 432, while the sum is 23.

The square root of 20616161 is about 4540.5022849901. The cubic root of 20616161 is about 274.2011461006.

Adding to 20616161 its reverse (16161602), we get a palindrome (36777763).

It can be divided in two parts, 20616 and 161, that multiplied together give a triangular number (3319176 = T₂₅₇₆).

The spelling of 20616161 in words is "twenty million, six hundred sixteen thousand, one hundred sixty-one".