21035570729 has 2 divisors, whose sum is σ = 21035570730. Its totient is φ = 21035570728.

The previous prime is 21035570657. The next prime is 21035570753. The reversal of 21035570729 is 92707553012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20829705625 + 205865104 = 144325^2 + 14348^2 .

It is a cyclic number.

It is not a de Polignac number, because 21035570729 - 2⁸ = 21035570473 is a prime.

It is not a weakly prime, because it can be changed into another prime (21035570779) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10517785364 + 10517785365.

It is an arithmetic number, because the mean of its divisors is an integer number (10517785365).

Almost surely, 2^21035570729 is an apocalyptic number.

It is an amenable number.

21035570729 is a deficient number, since it is larger than the sum of its proper divisors (1).

21035570729 is an equidigital number, since it uses as much as digits as its factorization.

21035570729 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 132300, while the sum is 41.

The spelling of 21035570729 in words is "twenty-one billion, thirty-five million, five hundred seventy thousand, seven hundred twenty-nine".