21111029 has 2 divisors, whose sum is σ = 21111030. Its totient is φ = 21111028.

The previous prime is 21111007. The next prime is 21111049. The reversal of 21111029 is 92011112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21022225 + 88804 = 4585^2 + 298^2 .

It is a cyclic number.

It is not a de Polignac number, because 21111029 - 2¹² = 21106933 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 21110998 and 21111016.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21111049) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10555514 + 10555515.

It is an arithmetic number, because the mean of its divisors is an integer number (10555515).

Almost surely, 2^21111029 is an apocalyptic number.

It is an amenable number.

21111029 is a deficient number, since it is larger than the sum of its proper divisors (1).

21111029 is an equidigital number, since it uses as much as digits as its factorization.

21111029 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 36, while the sum is 17.

The square root of 21111029 is about 4594.6739819056. The cubic root of 21111029 is about 276.3777864060.

The spelling of 21111029 in words is "twenty-one million, one hundred eleven thousand, twenty-nine".