21022000 has 80 divisors (see below), whose sum is σ = 53157312. Its totient is φ = 8025600.

The previous prime is 21021997. The next prime is 21022007. The reversal of 21022000 is 22012.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (80).

It is not an unprimeable number, because it can be changed into a prime (21022007) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 45772 + ... + 46228.

Almost surely, 2^21022000 is an apocalyptic number.

21022000 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 21022000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26578656).

21022000 is an abundant number, since it is smaller than the sum of its proper divisors (32135312).

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

21022000 is a wasteful number, since it uses less digits than its factorization.

21022000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 503 (or 487 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 7.

The square root of 21022000 is about 4584.9754634022. The cubic root of 21022000 is about 275.9887273979.

Adding to 21022000 its reverse (22012), we get a palindrome (21044012).

The spelling of 21022000 in words is "twenty-one million, twenty-two thousand".