21710208 has 64 divisors (see below), whose sum is σ = 62118000. Its totient is φ = 6678528.

The previous prime is 21710203. The next prime is 21710209. The reversal of 21710208 is 80201712.

It is a tau number, because it is divible by the number of its divisors (64).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21710201) 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, 2818 + ... + 7166.

Almost surely, 2^21710208 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21710208, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31059000).

21710208 is an abundant number, since it is smaller than the sum of its proper divisors (40407792).

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

21710208 is a wasteful number, since it uses less digits than its factorization.

21710208 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4379 (or 4367 counting only the distinct ones).

The product of its (nonzero) digits is 224, while the sum is 21.

The square root of 21710208 is about 4659.4214233100. The cubic root of 21710208 is about 278.9681750932.

The spelling of 21710208 in words is "twenty-one million, seven hundred ten thousand, two hundred eight".