21440700 has 90 divisors (see below), whose sum is σ = 69528536. Its totient is φ = 5715360.

The previous prime is 21440693. The next prime is 21440719. The reversal of 21440700 is 704412.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (90).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 6777 + ... + 9423.

Almost surely, 2^21440700 is an apocalyptic number.

21440700 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 21440700, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34764268).

21440700 is an abundant number, since it is smaller than the sum of its proper divisors (48087836).

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

21440700 is a wasteful number, since it uses less digits than its factorization.

21440700 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2673 (or 2657 counting only the distinct ones).

The product of its (nonzero) digits is 224, while the sum is 18.

The square root of 21440700 is about 4630.4103489864. The cubic root of 21440700 is about 277.8090056744.

The spelling of 21440700 in words is "twenty-one million, four hundred forty thousand, seven hundred".