205421634 has 48 divisors (see below), whose sum is σ = 486761184. Its totient is φ = 62092800.

The previous prime is 205421633. The next prime is 205421641. The reversal of 205421634 is 436124502.

205421634 is a `hidden beast` number, since 2 + 0 + 5 + 4 + 21 + 634 = 666.

205421634 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 205421598 and 205421607.

It is not an unprimeable number, because it can be changed into a prime (205421633) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 96162 + ... + 98274.

It is an arithmetic number, because the mean of its divisors is an integer number (10140858).

Almost surely, 2^205421634 is an apocalyptic number.

205421634 is an abundant number, since it is smaller than the sum of its proper divisors (281339550).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

205421634 is a wasteful number, since it uses less digits than its factorization.

205421634 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2623 (or 2620 counting only the distinct ones).

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

The square root of 205421634 is about 14332.5375980669. The cubic root of 205421634 is about 590.0408226087.

The spelling of 205421634 in words is "two hundred five million, four hundred twenty-one thousand, six hundred thirty-four".