205520131 has 4 divisors (see below), whose sum is σ = 216337000. Its totient is φ = 194703264.

The previous prime is 205520113. The next prime is 205520137. The reversal of 205520131 is 131025502.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-205520131 is a prime.

It is a super-2 number, since 2×205520131² = 84477048492514322, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (19), and also a Moran number because the ratio is a prime number: 10816849 = 205520131 / (2 + 0 + 5 + 5 + 2 + 0 + 1 + 3 + 1).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 205520099 and 205520108.

It is not an unprimeable number, because it can be changed into a prime (205520137) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5408406 + ... + 5408443.

It is an arithmetic number, because the mean of its divisors is an integer number (54084250).

Almost surely, 2^205520131 is an apocalyptic number.

205520131 is a deficient number, since it is larger than the sum of its proper divisors (10816869).

205520131 is a wasteful number, since it uses less digits than its factorization.

205520131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10816868.

The product of its (nonzero) digits is 300, while the sum is 19.

The square root of 205520131 is about 14335.9733188926. The cubic root of 205520131 is about 590.1351131717.

Adding to 205520131 its reverse (131025502), we get a palindrome (336545633).

The spelling of 205520131 in words is "two hundred five million, five hundred twenty thousand, one hundred thirty-one".