204155405 has 8 divisors (see below), whose sum is σ = 247155192. Its totient is φ = 161878528.

The previous prime is 204155387. The next prime is 204155449. The reversal of 204155405 is 504551402.

It can be written as a sum of positive squares in 4 ways, for example, as 16410601 + 187744804 = 4051^2 + 13702^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 204155405 - 2¹² = 204151309 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 180104 + ... + 181233.

It is an arithmetic number, because the mean of its divisors is an integer number (30894399).

Almost surely, 2^204155405 is an apocalyptic number.

It is an amenable number.

204155405 is a deficient number, since it is larger than the sum of its proper divisors (42999787).

204155405 is a wasteful number, since it uses less digits than its factorization.

204155405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 361455.

The product of its (nonzero) digits is 4000, while the sum is 26.

The square root of 204155405 is about 14288.2960845582. The cubic root of 204155405 is about 588.8259762241.

The spelling of 204155405 in words is "two hundred four million, one hundred fifty-five thousand, four hundred five".