21121222161401 has 2 divisors, whose sum is σ = 21121222161402. Its totient is φ = 21121222161400.

The previous prime is 21121222161379. The next prime is 21121222161469. The reversal of 21121222161401 is 10416122212112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11449594875625 + 9671627285776 = 3383725^2 + 3109924^2 .

It is a cyclic number.

It is not a de Polignac number, because 21121222161401 - 2¹⁸ = 21121221899257 is a prime.

It is a super-2 number, since 2×21121222161401² (a number of 27 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (21121222161001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10560611080700 + 10560611080701.

It is an arithmetic number, because the mean of its divisors is an integer number (10560611080701).

Almost surely, 2^{21121222161401} is an apocalyptic number.

It is an amenable number.

21121222161401 is a deficient number, since it is larger than the sum of its proper divisors (1).

21121222161401 is an equidigital number, since it uses as much as digits as its factorization.

21121222161401 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 768, while the sum is 26.

Adding to 21121222161401 its reverse (10416122212112), we get a palindrome (31537344373513).

The spelling of 21121222161401 in words is "twenty-one trillion, one hundred twenty-one billion, two hundred twenty-two million, one hundred sixty-one thousand, four hundred one".