205942153680 has 720 divisors, whose sum is σ = 767665866240. Its totient is φ = 49405593600.

The previous prime is 205942153667. The next prime is 205942153717. The reversal of 205942153680 is 86351249502.

205942153680 is a `hidden beast` number, since 2 + 0 + 5 + 94 + 21 + 536 + 8 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (720).

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 491508511 + ... + 491508929.

It is an arithmetic number, because the mean of its divisors is an integer number (1066202592).

Almost surely, 2^205942153680 is an apocalyptic number.

205942153680 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 205942153680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (383832933120).

205942153680 is an abundant number, since it is smaller than the sum of its proper divisors (561723712560).

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

205942153680 is a wasteful number, since it uses less digits than its factorization.

205942153680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 568 (or 540 counting only the distinct ones).

The product of its (nonzero) digits is 518400, while the sum is 45.

The spelling of 205942153680 in words is "two hundred five billion, nine hundred forty-two million, one hundred fifty-three thousand, six hundred eighty".