20835021 has 16 divisors (see below), whose sum is σ = 29151360. Its totient is φ = 13218240.

The previous prime is 20834981. The next prime is 20835037. The reversal of 20835021 is 12053802.

It is not a de Polignac number, because 20835021 - 2⁹ = 20834509 is a prime.

It is a super-3 number, since 3×20835021³ (a number of 23 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20835041) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4491 + ... + 7863.

It is an arithmetic number, because the mean of its divisors is an integer number (1821960).

Almost surely, 2^20835021 is an apocalyptic number.

It is an amenable number.

20835021 is a deficient number, since it is larger than the sum of its proper divisors (8316339).

20835021 is a wasteful number, since it uses less digits than its factorization.

20835021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3476.

The product of its (nonzero) digits is 480, while the sum is 21.

The square root of 20835021 is about 4564.5395167530. The cubic root of 20835021 is about 275.1680339440.

Adding to 20835021 its reverse (12053802), we get a palindrome (32888823).

The spelling of 20835021 in words is "twenty million, eight hundred thirty-five thousand, twenty-one".