252805409 has 4 divisors (see below), whose sum is σ = 253368900. Its totient is φ = 252241920.

The previous prime is 252805367. The next prime is 252805439. The reversal of 252805409 is 904508252.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 51165409 + 201640000 = 7153^2 + 14200^2 .

It is a cyclic number.

It is not a de Polignac number, because 252805409 - 2⁸ = 252805153 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (252805439) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 281072 + ... + 281969.

It is an arithmetic number, because the mean of its divisors is an integer number (63342225).

Almost surely, 2^252805409 is an apocalyptic number.

It is an amenable number.

252805409 is a deficient number, since it is larger than the sum of its proper divisors (563491).

252805409 is an equidigital number, since it uses as much as digits as its factorization.

252805409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 563490.

The product of its (nonzero) digits is 28800, while the sum is 35.

The square root of 252805409 is about 15899.8556282754. The cubic root of 252805409 is about 632.3081611857.

The spelling of 252805409 in words is "two hundred fifty-two million, eight hundred five thousand, four hundred nine".