21522829 has 2 divisors, whose sum is σ = 21522830. Its totient is φ = 21522828.

The previous prime is 21522791. The next prime is 21522859. The reversal of 21522829 is 92822512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18275625 + 3247204 = 4275^2 + 1802^2 .

It is a cyclic number.

It is not a de Polignac number, because 21522829 - 2⁷ = 21522701 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21522829.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21522859) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10761414 + 10761415.

It is an arithmetic number, because the mean of its divisors is an integer number (10761415).

Almost surely, 2^21522829 is an apocalyptic number.

It is an amenable number.

21522829 is a deficient number, since it is larger than the sum of its proper divisors (1).

21522829 is an equidigital number, since it uses as much as digits as its factorization.

21522829 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5760, while the sum is 31.

The square root of 21522829 is about 4639.2703090033. The cubic root of 21522829 is about 278.1632712390.

The spelling of 21522829 in words is "twenty-one million, five hundred twenty-two thousand, eight hundred twenty-nine".