205421072 has 40 divisors (see below), whose sum is σ = 404217432. Its totient is φ = 101120000.

The previous prime is 205421053. The next prime is 205421101. The reversal of 205421072 is 270124502.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 96510976 + 108910096 = 9824^2 + 10436^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 512072 + ... + 512472.

Almost surely, 2^205421072 is an apocalyptic number.

It is an amenable number.

205421072 is a deficient number, since it is larger than the sum of its proper divisors (198796360).

205421072 is a wasteful number, since it uses less digits than its factorization.

205421072 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 827 (or 821 counting only the distinct ones).

The product of its (nonzero) digits is 1120, while the sum is 23.

The square root of 205421072 is about 14332.5179923138. The cubic root of 205421072 is about 590.0402845231.

Adding to 205421072 its reverse (270124502), we get a palindrome (475545574).

The spelling of 205421072 in words is "two hundred five million, four hundred twenty-one thousand, seventy-two".