205312131 has 16 divisors (see below), whose sum is σ = 304389120. Its totient is φ = 136774440.

The previous prime is 205312127. The next prime is 205312139. The reversal of 205312131 is 131213502.

205312131 is a `hidden beast` number, since 2 + 0 + 531 + 2 + 131 = 666.

It is not a de Polignac number, because 205312131 - 2² = 205312127 is a prime.

It is a super-2 number, since 2×205312131² = 84306142271522322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (205312139) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 62746 + ... + 65936.

It is an arithmetic number, because the mean of its divisors is an integer number (19024320).

Almost surely, 2^205312131 is an apocalyptic number.

205312131 is a deficient number, since it is larger than the sum of its proper divisors (99076989).

205312131 is a wasteful number, since it uses less digits than its factorization.

205312131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5583 (or 5577 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 18.

The square root of 205312131 is about 14328.7170046728. The cubic root of 205312131 is about 589.9359606832.

Adding to 205312131 its reverse (131213502), we get a palindrome (336525633).

The spelling of 205312131 in words is "two hundred five million, three hundred twelve thousand, one hundred thirty-one".