205726290 has 256 divisors, whose sum is σ = 661893120. Its totient is φ = 39674880.

The previous prime is 205726289. The next prime is 205726307. The reversal of 205726290 is 92627502.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 2478589 + ... + 2478671.

It is an arithmetic number, because the mean of its divisors is an integer number (2585520).

Almost surely, 2^205726290 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 205726290, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (330946560).

205726290 is an abundant number, since it is smaller than the sum of its proper divisors (456166830).

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

205726290 is a wasteful number, since it uses less digits than its factorization.

205726290 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 177.

The product of its (nonzero) digits is 15120, while the sum is 33.

The square root of 205726290 is about 14343.1617853247. The cubic root of 205726290 is about 590.3323704215.

It can be divided in two parts, 20572 and 6290, that added together give a palindrome (26862).

The spelling of 205726290 in words is "two hundred five million, seven hundred twenty-six thousand, two hundred ninety".