205401220 has 12 divisors (see below), whose sum is σ = 431342604. Its totient is φ = 82160480.

The previous prime is 205401211. The next prime is 205401221. The reversal of 205401220 is 22104502.

It can be written as a sum of positive squares in 2 ways, for example, as 114618436 + 90782784 = 10706^2 + 9528^2 .

It is a super-2 number, since 2×205401220² = 84379322354976800, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 205401194 and 205401203.

It is not an unprimeable number, because it can be changed into a prime (205401221) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5135011 + ... + 5135050.

It is an arithmetic number, because the mean of its divisors is an integer number (35945217).

Almost surely, 2^205401220 is an apocalyptic number.

205401220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

205401220 is an abundant number, since it is smaller than the sum of its proper divisors (225941384).

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

205401220 is a wasteful number, since it uses less digits than its factorization.

205401220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10270070 (or 10270068 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 16.

The square root of 205401220 is about 14331.8254245578. The cubic root of 205401220 is about 590.0212766434.

Adding to 205401220 its reverse (22104502), we get a palindrome (227505722).

The spelling of 205401220 in words is "two hundred five million, four hundred one thousand, two hundred twenty".