21404000 has 48 divisors (see below), whose sum is σ = 52599456. Its totient is φ = 8560000.

The previous prime is 21403979. The next prime is 21404017. The reversal of 21404000 is 40412.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1325 + ... + 6675.

It is an arithmetic number, because the mean of its divisors is an integer number (1095822).

Almost surely, 2^21404000 is an apocalyptic number.

21404000 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 21404000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26299728).

21404000 is an abundant number, since it is smaller than the sum of its proper divisors (31195456).

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

21404000 is an equidigital number, since it uses as much as digits as its factorization.

21404000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5376 (or 5358 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 11.

The square root of 21404000 is about 4626.4457199885. The cubic root of 21404000 is about 277.6504067900.

Adding to 21404000 its reverse (40412), we get a palindrome (21444412).

The spelling of 21404000 in words is "twenty-one million, four hundred four thousand".