200121020205817 has 2 divisors, whose sum is σ = 200121020205818. Its totient is φ = 200121020205816.

The previous prime is 200121020205787. The next prime is 200121020205859. The reversal of 200121020205817 is 718502020121002.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 145318106601616 + 54802913604201 = 12054796^2 + 7402899^2 .

It is a cyclic number.

It is not a de Polignac number, because 200121020205817 - 2¹⁵ = 200121020173049 is a prime.

It is not a weakly prime, because it can be changed into another prime (200121020205917) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100060510102908 + 100060510102909.

It is an arithmetic number, because the mean of its divisors is an integer number (100060510102909).

Almost surely, 2^{200121020205817} is an apocalyptic number.

It is an amenable number.

200121020205817 is a deficient number, since it is larger than the sum of its proper divisors (1).

200121020205817 is an equidigital number, since it uses as much as digits as its factorization.

200121020205817 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4480, while the sum is 31.

Adding to 200121020205817 its reverse (718502020121002), we get a palindrome (918623040326819).

The spelling of 200121020205817 in words is "two hundred trillion, one hundred twenty-one billion, twenty million, two hundred five thousand, eight hundred seventeen".