209023181 has 2 divisors, whose sum is σ = 209023182. Its totient is φ = 209023180.

The previous prime is 209023169. The next prime is 209023193. The reversal of 209023181 is 181320902.

It is a balanced prime because it is at equal distance from previous prime (209023169) and next prime (209023193).

It can be written as a sum of positive squares in only one way, i.e., 206353225 + 2669956 = 14365^2 + 1634^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-209023181 is a prime.

It is a super-2 number, since 2×209023181² = 87381380390717522, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 209023181.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (209023081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 104511590 + 104511591.

It is an arithmetic number, because the mean of its divisors is an integer number (104511591).

Almost surely, 2^209023181 is an apocalyptic number.

It is an amenable number.

209023181 is a deficient number, since it is larger than the sum of its proper divisors (1).

209023181 is an equidigital number, since it uses as much as digits as its factorization.

209023181 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 864, while the sum is 26.

The square root of 209023181 is about 14457.6340042207. The cubic root of 209023181 is about 593.4691537390.

The spelling of 209023181 in words is "two hundred nine million, twenty-three thousand, one hundred eighty-one".