21335020 has 24 divisors (see below), whose sum is σ = 51204384. Its totient is φ = 7314816.

The previous prime is 21334997. The next prime is 21335023. The reversal of 21335020 is 2053312.

It is a junction number, because it is equal to n+sod(n) for n = 21334985 and 21335003.

It is not an unprimeable number, because it can be changed into a prime (21335023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 76057 + ... + 76336.

It is an arithmetic number, because the mean of its divisors is an integer number (2133516).

Almost surely, 2^21335020 is an apocalyptic number.

21335020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21335020 is an abundant number, since it is smaller than the sum of its proper divisors (29869364).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21335020 is a wasteful number, since it uses less digits than its factorization.

21335020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 152409 (or 152407 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 16.

The square root of 21335020 is about 4618.9847369308. The cubic root of 21335020 is about 277.3518187311.

Adding to 21335020 its reverse (2053312), we get a palindrome (23388332).

The spelling of 21335020 in words is "twenty-one million, three hundred thirty-five thousand, twenty".