21031024 has 40 divisors (see below), whose sum is σ = 49024640. Its totient is φ = 8538048.

The previous prime is 21031019. The next prime is 21031027. The reversal of 21031024 is 42013012.

It is a junction number, because it is equal to n+sod(n) for n = 21030995 and 21031013.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21031027) 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, 2814 + ... + 7069.

It is an arithmetic number, because the mean of its divisors is an integer number (1225616).

Almost surely, 2^21031024 is an apocalyptic number.

It is an amenable number.

21031024 is an abundant number, since it is smaller than the sum of its proper divisors (27993616).

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

21031024 is a wasteful number, since it uses less digits than its factorization.

21031024 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9917 (or 9911 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 13.

The square root of 21031024 is about 4585.9594416000. The cubic root of 21031024 is about 276.0282124770.

Adding to 21031024 its reverse (42013012), we get a palindrome (63044036).

The spelling of 21031024 in words is "twenty-one million, thirty-one thousand, twenty-four".