21220888 has 16 divisors (see below), whose sum is σ = 42850080. Its totient is φ = 9794208.

The previous prime is 21220877. The next prime is 21220907. The reversal of 21220888 is 88802212.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 101920 + ... + 102127.

It is an arithmetic number, because the mean of its divisors is an integer number (2678130).

Almost surely, 2^21220888 is an apocalyptic number.

It is an amenable number.

21220888 is an abundant number, since it is smaller than the sum of its proper divisors (21629192).

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

21220888 is a wasteful number, since it uses less digits than its factorization.

21220888 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 204066 (or 204062 counting only the distinct ones).

The product of its (nonzero) digits is 4096, while the sum is 31.

The square root of 21220888 is about 4606.6135066880. The cubic root of 21220888 is about 276.8563683413.

The spelling of 21220888 in words is "twenty-one million, two hundred twenty thousand, eight hundred eighty-eight".