253604561 has 4 divisors (see below), whose sum is σ = 289833792. Its totient is φ = 217375332.

The previous prime is 253604551. The next prime is 253604567. The reversal of 253604561 is 165406352.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 253604561 - 2¹⁴ = 253588177 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (253604567) 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, 18114605 + ... + 18114618.

It is an arithmetic number, because the mean of its divisors is an integer number (72458448).

Almost surely, 2^253604561 is an apocalyptic number.

It is an amenable number.

253604561 is a deficient number, since it is larger than the sum of its proper divisors (36229231).

253604561 is an equidigital number, since it uses as much as digits as its factorization.

253604561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36229230.

The product of its (nonzero) digits is 21600, while the sum is 32.

The square root of 253604561 is about 15924.9665933716. The cubic root of 253604561 is about 632.9737308233.

The spelling of 253604561 in words is "two hundred fifty-three million, six hundred four thousand, five hundred sixty-one".