205142403 has 4 divisors (see below), whose sum is σ = 273523208. Its totient is φ = 136761600.

The previous prime is 205142389. The next prime is 205142423. The reversal of 205142403 is 304241502.

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

It is not a de Polignac number, because 205142403 - 2²⁵ = 171587971 is a prime.

It is a super-2 number, since 2×205142403² = 84166811017228818, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 205142403.

It is not an unprimeable number, because it can be changed into a prime (205142423) 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, 34190398 + ... + 34190403.

It is an arithmetic number, because the mean of its divisors is an integer number (68380802).

Almost surely, 2^205142403 is an apocalyptic number.

205142403 is a deficient number, since it is larger than the sum of its proper divisors (68380805).

205142403 is an equidigital number, since it uses as much as digits as its factorization.

205142403 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68380804.

The product of its (nonzero) digits is 960, while the sum is 21.

The square root of 205142403 is about 14322.7931284369. The cubic root of 205142403 is about 589.7733525696.

Adding to 205142403 its reverse (304241502), we get a palindrome (509383905).

Subtracting 205142403 from its reverse (304241502), we obtain a palindrome (99099099).

The spelling of 205142403 in words is "two hundred five million, one hundred forty-two thousand, four hundred three".