20185261 has 2 divisors, whose sum is σ = 20185262. Its totient is φ = 20185260.

The previous prime is 20185259. The next prime is 20185271. The reversal of 20185261 is 16258102.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14516100 + 5669161 = 3810^2 + 2381^2 .

It is a cyclic number.

It is not a de Polignac number, because 20185261 - 2¹ = 20185259 is a prime.

Together with 20185259, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20185241) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10092630 + 10092631.

It is an arithmetic number, because the mean of its divisors is an integer number (10092631).

Almost surely, 2^20185261 is an apocalyptic number.

It is an amenable number.

20185261 is a deficient number, since it is larger than the sum of its proper divisors (1).

20185261 is an equidigital number, since it uses as much as digits as its factorization.

20185261 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 960, while the sum is 25.

The square root of 20185261 is about 4492.8010194087. The cubic root of 20185261 is about 272.2773132305.

The spelling of 20185261 in words is "twenty million, one hundred eighty-five thousand, two hundred sixty-one".