205122720 has 192 divisors, whose sum is σ = 719155584. Its totient is φ = 48721920.

The previous prime is 205122719. The next prime is 205122721. The reversal of 205122720 is 27221502.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (205122719) and next prime (205122721).

It is not an unprimeable number, because it can be changed into a prime (205122721) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 279474 + ... + 280206.

It is an arithmetic number, because the mean of its divisors is an integer number (3745602).

Almost surely, 2^205122720 is an apocalyptic number.

205122720 is a gapful number since it is divisible by the number (20) 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 205122720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (359577792).

205122720 is an abundant number, since it is smaller than the sum of its proper divisors (514032864).

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

205122720 is a wasteful number, since it uses less digits than its factorization.

205122720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 815 (or 807 counting only the distinct ones).

The product of its (nonzero) digits is 560, while the sum is 21.

The square root of 205122720 is about 14322.1059903912. The cubic root of 205122720 is about 589.7544894449.

It can be divided in two parts, 20512 and 2720, that added together give a palindrome (23232).

The spelling of 205122720 in words is "two hundred five million, one hundred twenty-two thousand, seven hundred twenty".