205420144121 has 8 divisors (see below), whose sum is σ = 209437797000. Its totient is φ = 201435023232.

The previous prime is 205420144103. The next prime is 205420144177. The reversal of 205420144121 is 121441024502.

It can be written as a sum of positive squares in 4 ways, for example, as 123932161600 + 81487982521 = 352040^2 + 285461^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 205420144121 - 2¹⁸ = 205419881977 is a prime.

It is a super-2 number, since 2×205420144121² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (205420104121) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8120246 + ... + 8145503.

It is an arithmetic number, because the mean of its divisors is an integer number (26179724625).

Almost surely, 2^205420144121 is an apocalyptic number.

It is an amenable number.

205420144121 is a deficient number, since it is larger than the sum of its proper divisors (4017652879).

205420144121 is a wasteful number, since it uses less digits than its factorization.

205420144121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16265995.

The product of its (nonzero) digits is 2560, while the sum is 26.

Adding to 205420144121 its reverse (121441024502), we get a palindrome (326861168623).

The spelling of 205420144121 in words is "two hundred five billion, four hundred twenty million, one hundred forty-four thousand, one hundred twenty-one".