205120318494 has 64 divisors (see below), whose sum is σ = 505772499456. Its totient is φ = 54005422464.

The previous prime is 205120318489. The next prime is 205120318511. The reversal of 205120318494 is 494813021502.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 504 + ... + 640500.

It is an arithmetic number, because the mean of its divisors is an integer number (7902695304).

Almost surely, 2^205120318494 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 205120318494, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (252886249728).

205120318494 is an abundant number, since it is smaller than the sum of its proper divisors (300652180962).

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

205120318494 is a wasteful number, since it uses less digits than its factorization.

205120318494 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 640609.

The product of its (nonzero) digits is 69120, while the sum is 39.

Adding to 205120318494 its reverse (494813021502), we get a palindrome (699933339996).

The spelling of 205120318494 in words is "two hundred five billion, one hundred twenty million, three hundred eighteen thousand, four hundred ninety-four".