21129529 has 8 divisors (see below), whose sum is σ = 21591360. Its totient is φ = 20672400.

The previous prime is 21129499. The next prime is 21129533. The reversal of 21129529 is 92592112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21129529 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21129529.

It is not an unprimeable number, because it can be changed into a prime (21124529) 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 in 7 ways as a sum of consecutive naturals, for example, 8799 + ... + 10939.

It is an arithmetic number, because the mean of its divisors is an integer number (2698920).

Almost surely, 2^21129529 is an apocalyptic number.

It is an amenable number.

21129529 is a deficient number, since it is larger than the sum of its proper divisors (461831).

21129529 is a wasteful number, since it uses less digits than its factorization.

21129529 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2351.

The product of its digits is 3240, while the sum is 31.

The square root of 21129529 is about 4596.6867415564. The cubic root of 21129529 is about 276.4584945553.

The spelling of 21129529 in words is "twenty-one million, one hundred twenty-nine thousand, five hundred twenty-nine".