205621416 has 320 divisors, whose sum is σ = 775716480. Its totient is φ = 49144320.

The previous prime is 205621393. The next prime is 205621421. The reversal of 205621416 is 614126502.

205621416 is a `hidden beast` number, since 20 + 5 + 621 + 4 + 16 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a self number, because there is not a number n which added to its sum of digits gives 205621416.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 648490 + ... + 648806.

It is an arithmetic number, because the mean of its divisors is an integer number (2424114).

Almost surely, 2^205621416 is an apocalyptic number.

205621416 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 205621416, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (387858240).

205621416 is an abundant number, since it is smaller than the sum of its proper divisors (570095064).

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

205621416 is a wasteful number, since it uses less digits than its factorization.

205621416 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 366 (or 353 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

The square root of 205621416 is about 14339.5054308020. The cubic root of 205621416 is about 590.2320412574.

Adding to 205621416 its reverse (614126502), we get a palindrome (819747918).

The spelling of 205621416 in words is "two hundred five million, six hundred twenty-one thousand, four hundred sixteen".