200121220261 has 2 divisors, whose sum is σ = 200121220262. Its totient is φ = 200121220260.

The previous prime is 200121220259. The next prime is 200121220291. The reversal of 200121220261 is 162022121002.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 168900450625 + 31220769636 = 410975^2 + 176694^2 .

It is a cyclic number.

It is not a de Polignac number, because 200121220261 - 2¹ = 200121220259 is a prime.

Together with 200121220259, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (200121220231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100060610130 + 100060610131.

It is an arithmetic number, because the mean of its divisors is an integer number (100060610131).

Almost surely, 2^200121220261 is an apocalyptic number.

It is an amenable number.

200121220261 is a deficient number, since it is larger than the sum of its proper divisors (1).

200121220261 is an equidigital number, since it uses as much as digits as its factorization.

200121220261 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 192, while the sum is 19.

Adding to 200121220261 its reverse (162022121002), we get a palindrome (362143341263).

The spelling of 200121220261 in words is "two hundred billion, one hundred twenty-one million, two hundred twenty thousand, two hundred sixty-one".