21021111219869 has 2 divisors, whose sum is σ = 21021111219870. Its totient is φ = 21021111219868.

The previous prime is 21021111219859. The next prime is 21021111220007. The reversal of 21021111219869 is 96891211112012.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11470922265625 + 9550188954244 = 3386875^2 + 3090338^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21021111219869 is a prime.

It is a super-2 number, since 2×21021111219869² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21021111219859) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10510555609934 + 10510555609935.

It is an arithmetic number, because the mean of its divisors is an integer number (10510555609935).

Almost surely, 2^{21021111219869} is an apocalyptic number.

It is an amenable number.

21021111219869 is a deficient number, since it is larger than the sum of its proper divisors (1).

21021111219869 is an equidigital number, since it uses as much as digits as its factorization.

21021111219869 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 31104, while the sum is 44.

The spelling of 21021111219869 in words is "twenty-one trillion, twenty-one billion, one hundred eleven million, two hundred nineteen thousand, eight hundred sixty-nine".