21529689 has 8 divisors (see below), whose sum is σ = 28798080. Its totient is φ = 14307216.

The previous prime is 21529681. The next prime is 21529691. The reversal of 21529689 is 98692512.

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

It is not a de Polignac number, because 21529689 - 2³ = 21529681 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21529689.

It is not an unprimeable number, because it can be changed into a prime (21529681) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10369 + ... + 12270.

It is an arithmetic number, because the mean of its divisors is an integer number (3599760).

Almost surely, 2^21529689 is an apocalyptic number.

It is an amenable number.

21529689 is a deficient number, since it is larger than the sum of its proper divisors (7268391).

21529689 is a wasteful number, since it uses less digits than its factorization.

21529689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22959.

The product of its digits is 77760, while the sum is 42.

The square root of 21529689 is about 4640.0095905073. The cubic root of 21529689 is about 278.1928212165.

The spelling of 21529689 in words is "twenty-one million, five hundred twenty-nine thousand, six hundred eighty-nine".