205421216 has 192 divisors, whose sum is σ = 557819136. Its totient is φ = 72483840.

The previous prime is 205421207. The next prime is 205421233. The reversal of 205421216 is 612124502.

It is a happy number.

205421216 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a hoax number, since the sum of its digits (23) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 205421191 and 205421200.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3875846 + ... + 3875898.

It is an arithmetic number, because the mean of its divisors is an integer number (2905308).

Almost surely, 2^205421216 is an apocalyptic number.

205421216 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 205421216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (278909568).

205421216 is an abundant number, since it is smaller than the sum of its proper divisors (352397920).

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

205421216 is a wasteful number, since it uses less digits than its factorization.

205421216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 116 (or 86 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 23.

The square root of 205421216 is about 14332.5230158545. The cubic root of 205421216 is about 590.0404223957.

Adding to 205421216 its reverse (612124502), we get a palindrome (817545718).

The spelling of 205421216 in words is "two hundred five million, four hundred twenty-one thousand, two hundred sixteen".