21522943829 has 2 divisors, whose sum is σ = 21522943830. Its totient is φ = 21522943828.

The previous prime is 21522943817. The next prime is 21522943837. The reversal of 21522943829 is 92834922512.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21520303204 + 2640625 = 146698^2 + 1625^2 .

It is a cyclic number.

It is not a de Polignac number, because 21522943829 - 2²⁴ = 21506166613 is a prime.

It is a super-2 number, since 2×21522943829² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21522943859) 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, 10761471914 + 10761471915.

It is an arithmetic number, because the mean of its divisors is an integer number (10761471915).

Almost surely, 2^21522943829 is an apocalyptic number.

It is an amenable number.

21522943829 is a deficient number, since it is larger than the sum of its proper divisors (1).

21522943829 is an equidigital number, since it uses as much as digits as its factorization.

21522943829 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 622080, while the sum is 47.

The spelling of 21522943829 in words is "twenty-one billion, five hundred twenty-two million, nine hundred forty-three thousand, eight hundred twenty-nine".