205251640 has 64 divisors (see below), whose sum is σ = 506619360. Its totient is φ = 74219520.

The previous prime is 205251601. The next prime is 205251667. The reversal of 205251640 is 46152502.

205251640 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 83712 + ... + 86128.

Almost surely, 2^205251640 is an apocalyptic number.

205251640 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 205251640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (253309680).

205251640 is an abundant number, since it is smaller than the sum of its proper divisors (301367720).

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

205251640 is a wasteful number, since it uses less digits than its factorization.

205251640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2632 (or 2628 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 25.

The square root of 205251640 is about 14326.6060181747. The cubic root of 205251640 is about 589.8780174899.

The spelling of 205251640 in words is "two hundred five million, two hundred fifty-one thousand, six hundred forty".