20518229 has 2 divisors, whose sum is σ = 20518230. Its totient is φ = 20518228.

The previous prime is 20518217. The next prime is 20518241. The reversal of 20518229 is 92281502.

It is a balanced prime because it is at equal distance from previous prime (20518217) and next prime (20518241).

It can be written as a sum of positive squares in only one way, i.e., 20232004 + 286225 = 4498^2 + 535^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20518229 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20518259) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10259114 + 10259115.

It is an arithmetic number, because the mean of its divisors is an integer number (10259115).

Almost surely, 2^20518229 is an apocalyptic number.

It is an amenable number.

20518229 is a deficient number, since it is larger than the sum of its proper divisors (1).

20518229 is an equidigital number, since it uses as much as digits as its factorization.

20518229 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2880, while the sum is 29.

The square root of 20518229 is about 4529.7051780442. The cubic root of 20518229 is about 273.7662817752.

The spelling of 20518229 in words is "twenty million, five hundred eighteen thousand, two hundred twenty-nine".