21973000 has 128 divisors (see below), whose sum is σ = 60952320. Its totient is φ = 7257600.

The previous prime is 21972997. The next prime is 21973001. The reversal of 21973000 is 37912.

It is not an unprimeable number, because it can be changed into a prime (21973001) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 300964 + ... + 301036.

It is an arithmetic number, because the mean of its divisors is an integer number (476190).

Almost surely, 2^21973000 is an apocalyptic number.

21973000 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 21973000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30476160).

21973000 is an abundant number, since it is smaller than the sum of its proper divisors (38979320).

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

21973000 is a wasteful number, since it uses less digits than its factorization.

21973000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 144 (or 130 counting only the distinct ones).

The product of its (nonzero) digits is 378, while the sum is 22.

The square root of 21973000 is about 4687.5366665233. The cubic root of 21973000 is about 280.0892572582.

The spelling of 21973000 in words is "twenty-one million, nine hundred seventy-three thousand".