21012212122127 has 2 divisors, whose sum is σ = 21012212122128. Its totient is φ = 21012212122126.

The previous prime is 21012212122117. The next prime is 21012212122163. The reversal of 21012212122127 is 72122121221012.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21012212122127 - 2⁸ = 21012212121871 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21012212122096 and 21012212122105.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21012212122117) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10506106061063 + 10506106061064.

It is an arithmetic number, because the mean of its divisors is an integer number (10506106061064).

Almost surely, 2^{21012212122127} is an apocalyptic number.

21012212122127 is a deficient number, since it is larger than the sum of its proper divisors (1).

21012212122127 is an equidigital number, since it uses as much as digits as its factorization.

21012212122127 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 896, while the sum is 26.

Adding to 21012212122127 its reverse (72122121221012), we get a palindrome (93134333343139).

The spelling of 21012212122127 in words is "twenty-one trillion, twelve billion, two hundred twelve million, one hundred twenty-two thousand, one hundred twenty-seven".