205172340 has 96 divisors (see below), whose sum is σ = 588282240. Its totient is φ = 53415936.

The previous prime is 205172327. The next prime is 205172347. The reversal of 205172340 is 43271502.

It is a self number, because there is not a number n which added to its sum of digits gives 205172340.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205172347) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 608652 + ... + 608988.

It is an arithmetic number, because the mean of its divisors is an integer number (6127940).

Almost surely, 2^205172340 is an apocalyptic number.

205172340 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 205172340, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (294141120).

205172340 is an abundant number, since it is smaller than the sum of its proper divisors (383109900).

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

205172340 is a wasteful number, since it uses less digits than its factorization.

205172340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 561 (or 559 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 24.

The square root of 205172340 is about 14323.8381727804. The cubic root of 205172340 is about 589.8020402613.

The spelling of 205172340 in words is "two hundred five million, one hundred seventy-two thousand, three hundred forty".