21704000 has 56 divisors (see below), whose sum is σ = 53769768. Its totient is φ = 8678400.

The previous prime is 21703993. The next prime is 21704009. The reversal of 21704000 is 40712.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 322624 + 21381376 = 568^2 + 4624^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21704009) 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, 6644 + ... + 9356.

Almost surely, 2^21704000 is an apocalyptic number.

21704000 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 21704000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26884884).

21704000 is an abundant number, since it is smaller than the sum of its proper divisors (32065768).

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

21704000 is an equidigital number, since it uses as much as digits as its factorization.

21704000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2740 (or 2720 counting only the distinct ones).

The product of its (nonzero) digits is 56, while the sum is 14.

The square root of 21704000 is about 4658.7551985482. The cubic root of 21704000 is about 278.9415823873.

Adding to 21704000 its reverse (40712), we get a palindrome (21744712).

The spelling of 21704000 in words is "twenty-one million, seven hundred four thousand".