20538361 has 2 divisors, whose sum is σ = 20538362. Its totient is φ = 20538360.

The previous prime is 20538359. The next prime is 20538403. The reversal of 20538361 is 16383502.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14584761 + 5953600 = 3819^2 + 2440^2 .

It is a cyclic number.

It is not a de Polignac number, because 20538361 - 2¹ = 20538359 is a prime.

Together with 20538359, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (20532361) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10269180 + 10269181.

It is an arithmetic number, because the mean of its divisors is an integer number (10269181).

Almost surely, 2^20538361 is an apocalyptic number.

It is an amenable number.

20538361 is a deficient number, since it is larger than the sum of its proper divisors (1).

20538361 is an equidigital number, since it uses as much as digits as its factorization.

20538361 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4320, while the sum is 28.

The square root of 20538361 is about 4531.9268528960. The cubic root of 20538361 is about 273.8557901695.

The spelling of 20538361 in words is "twenty million, five hundred thirty-eight thousand, three hundred sixty-one".