21241020 has 24 divisors (see below), whose sum is σ = 59475024. Its totient is φ = 5664256.

The previous prime is 21241013. The next prime is 21241037. The reversal of 21241020 is 2014212.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 21240987 and 21241005.

It is a congruent number.

It is an unprimeable number.

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, 176949 + ... + 177068.

It is an arithmetic number, because the mean of its divisors is an integer number (2478126).

Almost surely, 2^21241020 is an apocalyptic number.

21241020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21241020 is an abundant number, since it is smaller than the sum of its proper divisors (38234004).

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

21241020 is a wasteful number, since it uses less digits than its factorization.

21241020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 354029 (or 354027 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 12.

The square root of 21241020 is about 4608.7981079670. The cubic root of 21241020 is about 276.9438907670.

Adding to 21241020 its reverse (2014212), we get a palindrome (23255232).

The spelling of 21241020 in words is "twenty-one million, two hundred forty-one thousand, twenty".