21021240029 has 2 divisors, whose sum is σ = 21021240030. Its totient is φ = 21021240028.

The previous prime is 21021240001. The next prime is 21021240041. The reversal of 21021240029 is 92004212012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18905700004 + 2115540025 = 137498^2 + 45995^2 .

It is a cyclic number.

It is not a de Polignac number, because 21021240029 - 2²⁴ = 21004462813 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21021239986 and 21021240013.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21021240059) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10510620014 + 10510620015.

It is an arithmetic number, because the mean of its divisors is an integer number (10510620015).

Almost surely, 2^21021240029 is an apocalyptic number.

It is an amenable number.

21021240029 is a deficient number, since it is larger than the sum of its proper divisors (1).

21021240029 is an equidigital number, since it uses as much as digits as its factorization.

21021240029 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 576, while the sum is 23.

The spelling of 21021240029 in words is "twenty-one billion, twenty-one million, two hundred forty thousand, twenty-nine".