205434621 has 12 divisors (see below), whose sum is σ = 339130272. Its totient is φ = 117391176.

The previous prime is 205434611. The next prime is 205434709. The reversal of 205434621 is 126434502.

205434621 is a `hidden beast` number, since 2 + 0 + 5 + 4 + 34 + 621 = 666.

It is not a de Polignac number, because 205434621 - 2⁹ = 205434109 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205434611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1630371 + ... + 1630496.

It is an arithmetic number, because the mean of its divisors is an integer number (28260856).

Almost surely, 2^205434621 is an apocalyptic number.

205434621 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

205434621 is a deficient number, since it is larger than the sum of its proper divisors (133695651).

205434621 is a wasteful number, since it uses less digits than its factorization.

205434621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3260880 (or 3260877 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 27.

The square root of 205434621 is about 14332.9906509423. The cubic root of 205434621 is about 590.0532567075.

The spelling of 205434621 in words is "two hundred five million, four hundred thirty-four thousand, six hundred twenty-one".