21103291829 has 2 divisors, whose sum is σ = 21103291830. Its totient is φ = 21103291828.

The previous prime is 21103291817. The next prime is 21103291879. The reversal of 21103291829 is 92819230112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19651834225 + 1451457604 = 140185^2 + 38098^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21103291829 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21103291792 and 21103291801.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21103291879) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10551645914 + 10551645915.

It is an arithmetic number, because the mean of its divisors is an integer number (10551645915).

Almost surely, 2^21103291829 is an apocalyptic number.

It is an amenable number.

21103291829 is a deficient number, since it is larger than the sum of its proper divisors (1).

21103291829 is an equidigital number, since it uses as much as digits as its factorization.

21103291829 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15552, while the sum is 38.

The spelling of 21103291829 in words is "twenty-one billion, one hundred three million, two hundred ninety-one thousand, eight hundred twenty-nine".