205421340 has 48 divisors (see below), whose sum is σ = 576213120. Its totient is φ = 54680640.

The previous prime is 205421339. The next prime is 205421341. The reversal of 205421340 is 43124502.

It is an interprime number because it is at equal distance from previous prime (205421339) and next prime (205421341).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205421341) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 34375 + ... + 39905.

It is an arithmetic number, because the mean of its divisors is an integer number (12004440).

Almost surely, 2^205421340 is an apocalyptic number.

205421340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

205421340 is an abundant number, since it is smaller than the sum of its proper divisors (370791780).

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

205421340 is a wasteful number, since it uses less digits than its factorization.

205421340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6162 (or 6160 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 21.

The square root of 205421340 is about 14332.5273416798. The cubic root of 205421340 is about 590.0405411192.

Adding to 205421340 its reverse (43124502), we get a palindrome (248545842).

It can be divided in two parts, 205421 and 340, that added together give a triangular number (205761 = T₆₄₁).

The spelling of 205421340 in words is "two hundred five million, four hundred twenty-one thousand, three hundred forty".