252181409 has 2 divisors, whose sum is σ = 252181410. Its totient is φ = 252181408.

The previous prime is 252181393. The next prime is 252181439. The reversal of 252181409 is 904181252.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 143041600 + 109139809 = 11960^2 + 10447^2 .

It is a cyclic number.

It is not a de Polignac number, because 252181409 - 2⁴ = 252181393 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is equal to p_13792109 and since 252181409 and 13792109 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (252181439) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 126090704 + 126090705.

It is an arithmetic number, because the mean of its divisors is an integer number (126090705).

Almost surely, 2^252181409 is an apocalyptic number.

It is an amenable number.

252181409 is a deficient number, since it is larger than the sum of its proper divisors (1).

252181409 is an equidigital number, since it uses as much as digits as its factorization.

252181409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5760, while the sum is 32.

The square root of 252181409 is about 15880.2206848646. The cubic root of 252181409 is about 631.7874901403.

The spelling of 252181409 in words is "two hundred fifty-two million, one hundred eighty-one thousand, four hundred nine".