210421420042081 has 2 divisors, whose sum is σ = 210421420042082. Its totient is φ = 210421420042080.

The previous prime is 210421420042073. The next prime is 210421420042109. The reversal of 210421420042081 is 180240024124012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 133357250937681 + 77064169104400 = 11548041^2 + 8778620^2 .

It is a cyclic number.

It is not a de Polignac number, because 210421420042081 - 2³ = 210421420042073 is a prime.

It is a super-2 number, since 2×210421420042081² (a number of 29 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (210421420042051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105210710021040 + 105210710021041.

It is an arithmetic number, because the mean of its divisors is an integer number (105210710021041).

Almost surely, 2^{210421420042081} is an apocalyptic number.

It is an amenable number.

210421420042081 is a deficient number, since it is larger than the sum of its proper divisors (1).

210421420042081 is an equidigital number, since it uses as much as digits as its factorization.

210421420042081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8192, while the sum is 31.

Adding to 210421420042081 its reverse (180240024124012), we get a palindrome (390661444166093).

The spelling of 210421420042081 in words is "two hundred ten trillion, four hundred twenty-one billion, four hundred twenty million, forty-two thousand, eighty-one".