21021122122061 has 2 divisors, whose sum is σ = 21021122122062. Its totient is φ = 21021122122060.

The previous prime is 21021122122057. The next prime is 21021122122069. The reversal of 21021122122061 is 16022122112012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20871831844900 + 149290277161 = 4568570^2 + 386381^2 .

It is a cyclic number.

It is not a de Polignac number, because 21021122122061 - 2² = 21021122122057 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21021122122069) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10510561061030 + 10510561061031.

It is an arithmetic number, because the mean of its divisors is an integer number (10510561061031).

Almost surely, 2^{21021122122061} is an apocalyptic number.

It is an amenable number.

21021122122061 is a deficient number, since it is larger than the sum of its proper divisors (1).

21021122122061 is an equidigital number, since it uses as much as digits as its factorization.

21021122122061 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 384, while the sum is 23.

Adding to 21021122122061 its reverse (16022122112012), we get a palindrome (37043244234073).

The spelling of 21021122122061 in words is "twenty-one trillion, twenty-one billion, one hundred twenty-two million, one hundred twenty-two thousand, sixty-one".