204157581 has 4 divisors (see below), whose sum is σ = 272210112. Its totient is φ = 136105052.

The previous prime is 204157559. The next prime is 204157609. The reversal of 204157581 is 185751402.

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 204157581 - 2⁶ = 204157517 is a prime.

It is a super-2 number, since 2×204157581² = 83360635759543122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (204157511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 34026261 + ... + 34026266.

It is an arithmetic number, because the mean of its divisors is an integer number (68052528).

Almost surely, 2^204157581 is an apocalyptic number.

It is an amenable number.

204157581 is a deficient number, since it is larger than the sum of its proper divisors (68052531).

204157581 is an equidigital number, since it uses as much as digits as its factorization.

204157581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68052530.

The product of its (nonzero) digits is 11200, while the sum is 33.

The square root of 204157581 is about 14288.3722305937. The cubic root of 204157581 is about 588.8280682265.

The spelling of 204157581 in words is "two hundred four million, one hundred fifty-seven thousand, five hundred eighty-one".