205421310 has 24 divisors (see below), whose sum is σ = 534095640. Its totient is φ = 54778992.

The previous prime is 205421309. The next prime is 205421311. The reversal of 205421310 is 13124502.

It is an interprime number because it is at equal distance from previous prime (205421309) and next prime (205421311).

It is a super-2 number, since 2×205421310² = 84395829204232200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205421311) 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, 1141140 + ... + 1141319.

It is an arithmetic number, because the mean of its divisors is an integer number (22253985).

Almost surely, 2^205421310 is an apocalyptic number.

205421310 is an abundant number, since it is smaller than the sum of its proper divisors (328674330).

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

205421310 is a wasteful number, since it uses less digits than its factorization.

205421310 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2282472 (or 2282469 counting only the distinct ones).

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

The square root of 205421310 is about 14332.5262951093. The cubic root of 205421310 is about 590.0405123958.

Adding to 205421310 its reverse (13124502), we get a palindrome (218545812).

The spelling of 205421310 in words is "two hundred five million, four hundred twenty-one thousand, three hundred ten".