204429781 has 2 divisors, whose sum is σ = 204429782. Its totient is φ = 204429780.

The previous prime is 204429767. The next prime is 204429791. The reversal of 204429781 is 187924402.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 144985681 + 59444100 = 12041^2 + 7710^2 .

It is a cyclic number.

It is not a de Polignac number, because 204429781 - 2¹⁷ = 204298709 is a prime.

It is a super-2 number, since 2×204429781² = 83583070719415922, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 204429781.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (204429761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102214890 + 102214891.

It is an arithmetic number, because the mean of its divisors is an integer number (102214891).

Almost surely, 2^204429781 is an apocalyptic number.

It is an amenable number.

204429781 is a deficient number, since it is larger than the sum of its proper divisors (1).

204429781 is an equidigital number, since it uses as much as digits as its factorization.

204429781 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 32256, while the sum is 37.

The square root of 204429781 is about 14297.8942855233. The cubic root of 204429781 is about 589.0896436554.

The spelling of 204429781 in words is "two hundred four million, four hundred twenty-nine thousand, seven hundred eighty-one".