20211202221961 has 2 divisors, whose sum is σ = 20211202221962. Its totient is φ = 20211202221960.

The previous prime is 20211202221949. The next prime is 20211202222061. The reversal of 20211202221961 is 16912220211202.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19672418329600 + 538783892361 = 4435360^2 + 734019^2 .

It is a cyclic number.

It is not a de Polignac number, because 20211202221961 - 2¹⁷ = 20211202090889 is a prime.

It is not a weakly prime, because it can be changed into another prime (20211202221761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10105601110980 + 10105601110981.

It is an arithmetic number, because the mean of its divisors is an integer number (10105601110981).

Almost surely, 2^{20211202221961} is an apocalyptic number.

It is an amenable number.

20211202221961 is a deficient number, since it is larger than the sum of its proper divisors (1).

20211202221961 is an equidigital number, since it uses as much as digits as its factorization.

20211202221961 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3456, while the sum is 31.

The spelling of 20211202221961 in words is "twenty trillion, two hundred eleven billion, two hundred two million, two hundred twenty-one thousand, nine hundred sixty-one".