205421031 has 6 divisors (see below), whose sum is σ = 296719280. Its totient is φ = 136947348.

The previous prime is 205421017. The next prime is 205421039. The reversal of 205421031 is 130124502.

205421031 is a `hidden beast` number, since 20 + 542 + 103 + 1 = 666.

It is not a de Polignac number, because 205421031 - 2⁷ = 205420903 is a prime.

It is a super-2 number, since 2×205421031² = 84395599954205922, which contains 22 as substring.

It is a Duffinian number.

It is a zygodrome in base 2.

It is a junction number, because it is equal to n+sod(n) for n = 205420995 and 205421013.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205421039) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 11412271 + ... + 11412288.

Almost surely, 2^205421031 is an apocalyptic number.

205421031 is a deficient number, since it is larger than the sum of its proper divisors (91298249).

205421031 is a wasteful number, since it uses less digits than its factorization.

205421031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22824565 (or 22824562 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 205421031 is about 14332.5165619998. The cubic root of 205421031 is about 590.0402452677.

Adding to 205421031 its reverse (130124502), we get a palindrome (335545533).

The spelling of 205421031 in words is "two hundred five million, four hundred twenty-one thousand, thirty-one".