21023000 has 32 divisors (see below), whose sum is σ = 49196160. Its totient is φ = 8408800.

The previous prime is 21022997. The next prime is 21023003. The reversal of 21023000 is 32012.

It is an interprime number because it is at equal distance from previous prime (21022997) and next prime (21023003).

It is a Harshad number since it is a multiple of its sum of digits (8).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21023003) 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, 9512 + ... + 11511.

It is an arithmetic number, because the mean of its divisors is an integer number (1537380).

Almost surely, 2^21023000 is an apocalyptic number.

21023000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21023000 is an abundant number, since it is smaller than the sum of its proper divisors (28173160).

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

21023000 is a wasteful number, since it uses less digits than its factorization.

21023000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21044 (or 21030 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 8.

The square root of 21023000 is about 4585.0845139430. The cubic root of 21023000 is about 275.9931035174.

Adding to 21023000 its reverse (32012), we get a palindrome (21055012).

The spelling of 21023000 in words is "twenty-one million, twenty-three thousand".