21101208 has 48 divisors (see below), whose sum is σ = 53938920. Its totient is φ = 6878976.

The previous prime is 21101207. The next prime is 21101209. The reversal of 21101208 is 80210112.

It is an interprime number because it is at equal distance from previous prime (21101207) and next prime (21101209).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21101207) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 67260 + ... + 67572.

Almost surely, 2^21101208 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 21101208, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26969460).

21101208 is an abundant number, since it is smaller than the sum of its proper divisors (32837712).

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

21101208 is a wasteful number, since it uses less digits than its factorization.

21101208 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 428 (or 371 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 15.

The square root of 21101208 is about 4593.6051201643. The cubic root of 21101208 is about 276.3349221248.

The spelling of 21101208 in words is "twenty-one million, one hundred one thousand, two hundred eight".