21629533 has 2 divisors, whose sum is σ = 21629534. Its totient is φ = 21629532.

The previous prime is 21629527. The next prime is 21629557. The reversal of 21629533 is 33592612.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17455684 + 4173849 = 4178^2 + 2043^2 .

It is a cyclic number.

It is not a de Polignac number, because 21629533 - 2⁵ = 21629501 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21629495 and 21629504.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21629513) 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, 10814766 + 10814767.

It is an arithmetic number, because the mean of its divisors is an integer number (10814767).

Almost surely, 2^21629533 is an apocalyptic number.

It is an amenable number.

21629533 is a deficient number, since it is larger than the sum of its proper divisors (1).

21629533 is an equidigital number, since it uses as much as digits as its factorization.

21629533 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9720, while the sum is 31.

The square root of 21629533 is about 4650.7561750752. The cubic root of 21629533 is about 278.6221981791.

The spelling of 21629533 in words is "twenty-one million, six hundred twenty-nine thousand, five hundred thirty-three".