21923000 has 64 divisors (see below), whose sum is σ = 55991520. Its totient is φ = 7968000.

The previous prime is 21922993. The next prime is 21923021. The reversal of 21923000 is 32912.

It is a self number, because there is not a number n which added to its sum of digits gives 21923000.

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 15 ways as a sum of consecutive naturals, for example, 10004 + ... + 11996.

Almost surely, 2^21923000 is an apocalyptic number.

21923000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21923000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27995760).

21923000 is an abundant number, since it is smaller than the sum of its proper divisors (34068520).

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

21923000 is a wasteful number, since it uses less digits than its factorization.

21923000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2025 (or 2011 counting only the distinct ones).

The product of its (nonzero) digits is 108, while the sum is 17.

The square root of 21923000 is about 4682.2003374482. The cubic root of 21923000 is about 279.8766463450.

Adding to 21923000 its reverse (32912), we get a palindrome (21955912).

The spelling of 21923000 in words is "twenty-one million, nine hundred twenty-three thousand".