21053829 has 8 divisors (see below), whose sum is σ = 28147360. Its totient is φ = 13998096.

The previous prime is 21053783. The next prime is 21053831. The reversal of 21053829 is 92835012.

It is a happy number.

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

It is a de Polignac number, because none of the positive numbers 2^k-21053829 is a prime.

It is a super-2 number, since 2×21053829² = 886527431122482, 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 = 21053796 and 21053805.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21053839) 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, 8122 + ... + 10395.

It is an arithmetic number, because the mean of its divisors is an integer number (3518420).

Almost surely, 2^21053829 is an apocalyptic number.

It is an amenable number.

21053829 is a deficient number, since it is larger than the sum of its proper divisors (7093531).

21053829 is a wasteful number, since it uses less digits than its factorization.

21053829 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18899.

The product of its (nonzero) digits is 4320, while the sum is 30.

The square root of 21053829 is about 4588.4451614899. The cubic root of 21053829 is about 276.1279468740.

The spelling of 21053829 in words is "twenty-one million, fifty-three thousand, eight hundred twenty-nine".