21525829 has 8 divisors (see below), whose sum is σ = 23267552. Its totient is φ = 19796400.

The previous prime is 21525793. The next prime is 21525853. The reversal of 21525829 is 92852512.

It is a happy number.

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

It is not a de Polignac number, because 21525829 - 2²³ = 13137221 is a prime.

It is a super-2 number, since 2×21525829² = 926722628274482, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21525794 and 21525803.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21525899) 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, 754 + ... + 6604.

It is an arithmetic number, because the mean of its divisors is an integer number (2908444).

Almost surely, 2^21525829 is an apocalyptic number.

It is an amenable number.

21525829 is a deficient number, since it is larger than the sum of its proper divisors (1741723).

21525829 is a wasteful number, since it uses less digits than its factorization.

21525829 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6147.

The product of its digits is 14400, while the sum is 34.

The square root of 21525829 is about 4639.5936244460. The cubic root of 21525829 is about 278.1761947421.

The spelling of 21525829 in words is "twenty-one million, five hundred twenty-five thousand, eight hundred twenty-nine".