21023412 has 24 divisors (see below), whose sum is σ = 49156800. Its totient is φ = 6993216.

The previous prime is 21023393. The next prime is 21023413. The reversal of 21023412 is 21432012.

It is a junction number, because it is equal to n+sod(n) for n = 21023391 and 21023400.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21023413) 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, 5289 + ... + 8367.

It is an arithmetic number, because the mean of its divisors is an integer number (2048200).

Almost surely, 2^21023412 is an apocalyptic number.

It is an amenable number.

21023412 is an abundant number, since it is smaller than the sum of its proper divisors (28133388).

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

21023412 is a wasteful number, since it uses less digits than its factorization.

21023412 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3655 (or 3653 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 15.

The square root of 21023412 is about 4585.1294420114. The cubic root of 21023412 is about 275.9949064382.

Adding to 21023412 its reverse (21432012), we get a palindrome (42455424).

The spelling of 21023412 in words is "twenty-one million, twenty-three thousand, four hundred twelve".