21020024 has 32 divisors (see below), whose sum is σ = 42094080. Its totient is φ = 9805824.

The previous prime is 21020017. The next prime is 21020029. The reversal of 21020024 is 42002012.

It is a junction number, because it is equal to n+sod(n) for n = 21019987 and 21020014.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21020029) 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, 16664 + ... + 17880.

It is an arithmetic number, because the mean of its divisors is an integer number (1315440).

Almost surely, 2^21020024 is an apocalyptic number.

It is an amenable number.

21020024 is an abundant number, since it is smaller than the sum of its proper divisors (21074056).

21020024 is a wasteful number, since it uses less digits than its factorization.

21020024 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1367 (or 1363 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 11.

The square root of 21020024 is about 4584.7599719069. The cubic root of 21020024 is about 275.9800797777.

Adding to 21020024 its reverse (42002012), we get a palindrome (63022036).

The spelling of 21020024 in words is "twenty-one million, twenty thousand, twenty-four".