21012100121827 has 2 divisors, whose sum is σ = 21012100121828. Its totient is φ = 21012100121826.

The previous prime is 21012100121797. The next prime is 21012100122007. The reversal of 21012100121827 is 72812100121012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21012100121827 - 2⁷ = 21012100121699 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21012100121795 and 21012100121804.

It is not a weakly prime, because it can be changed into another prime (21012100521827) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10506050060913 + 10506050060914.

It is an arithmetic number, because the mean of its divisors is an integer number (10506050060914).

Almost surely, 2^{21012100121827} is an apocalyptic number.

21012100121827 is a deficient number, since it is larger than the sum of its proper divisors (1).

21012100121827 is an equidigital number, since it uses as much as digits as its factorization.

21012100121827 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 896, while the sum is 28.

Adding to 21012100121827 its reverse (72812100121012), we get a palindrome (93824200242839).

The spelling of 21012100121827 in words is "twenty-one trillion, twelve billion, one hundred million, one hundred twenty-one thousand, eight hundred twenty-seven".