205406420 has 24 divisors (see below), whose sum is σ = 446229000. Its totient is φ = 79329152.

The previous prime is 205406293. The next prime is 205406423. The reversal of 205406420 is 24604502.

It can be written as a sum of positive squares in 4 ways, for example, as 73753744 + 131652676 = 8588^2 + 11474^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205406423) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 176495 + ... + 177654.

It is an arithmetic number, because the mean of its divisors is an integer number (18592875).

Almost surely, 2^205406420 is an apocalyptic number.

205406420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

205406420 is an abundant number, since it is smaller than the sum of its proper divisors (240822580).

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

205406420 is a wasteful number, since it uses less digits than its factorization.

205406420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 354187 (or 354185 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 23.

The square root of 205406420 is about 14332.0068378437. The cubic root of 205406420 is about 590.0262556543.

The spelling of 205406420 in words is "two hundred five million, four hundred six thousand, four hundred twenty".