21210355429 has 2 divisors, whose sum is σ = 21210355430. Its totient is φ = 21210355428.

The previous prime is 21210355421. The next prime is 21210355457. The reversal of 21210355429 is 92455301212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13036387329 + 8173968100 = 114177^2 + 90410^2 .

It is a cyclic number.

It is not a de Polignac number, because 21210355429 - 2³ = 21210355421 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21210355394 and 21210355403.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21210355421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10605177714 + 10605177715.

It is an arithmetic number, because the mean of its divisors is an integer number (10605177715).

Almost surely, 2^21210355429 is an apocalyptic number.

It is an amenable number.

21210355429 is a deficient number, since it is larger than the sum of its proper divisors (1).

21210355429 is an equidigital number, since it uses as much as digits as its factorization.

21210355429 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 21600, while the sum is 34.

The spelling of 21210355429 in words is "twenty-one billion, two hundred ten million, three hundred fifty-five thousand, four hundred twenty-nine".