205121026001 has 4 divisors (see below), whose sum is σ = 205121932212. Its totient is φ = 205120119792.

The previous prime is 205121025953. The next prime is 205121026051. The reversal of 205121026001 is 100620121502.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 100620121502 = 2 ⋅50310060751.

It can be written as a sum of positive squares in 2 ways, for example, as 151955734225 + 53165291776 = 389815^2 + 230576^2 .

It is a cyclic number.

It is not a de Polignac number, because 205121026001 - 2¹⁴ = 205121009617 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (205121026051) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 206255 + ... + 672891.

It is an arithmetic number, because the mean of its divisors is an integer number (51280483053).

Almost surely, 2^205121026001 is an apocalyptic number.

It is an amenable number.

205121026001 is a deficient number, since it is larger than the sum of its proper divisors (906211).

205121026001 is an equidigital number, since it uses as much as digits as its factorization.

205121026001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 906210.

The product of its (nonzero) digits is 240, while the sum is 20.

Adding to 205121026001 its reverse (100620121502), we get a palindrome (305741147503).

The spelling of 205121026001 in words is "two hundred five billion, one hundred twenty-one million, twenty-six thousand, one".