21799529 has 2 divisors, whose sum is σ = 21799530. Its totient is φ = 21799528.

The previous prime is 21799523. The next prime is 21799553. The reversal of 21799529 is 92599712.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12588304 + 9211225 = 3548^2 + 3035^2 .

It is a cyclic number.

It is not a de Polignac number, because 21799529 - 2⁴ = 21799513 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21799529.

It is not a weakly prime, because it can be changed into another prime (21799523) 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, 10899764 + 10899765.

It is an arithmetic number, because the mean of its divisors is an integer number (10899765).

Almost surely, 2^21799529 is an apocalyptic number.

It is an amenable number.

21799529 is a deficient number, since it is larger than the sum of its proper divisors (1).

21799529 is an equidigital number, since it uses as much as digits as its factorization.

21799529 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 102060, while the sum is 44.

The square root of 21799529 is about 4668.9965731407. The cubic root of 21799529 is about 279.3502322615.

The spelling of 21799529 in words is "twenty-one million, seven hundred ninety-nine thousand, five hundred twenty-nine".