21212048 has 80 divisors (see below), whose sum is σ = 49330176. Its totient is φ = 8709120.

The previous prime is 21212033. The next prime is 21212071. The reversal of 21212048 is 84021212.

It is a happy 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 15 ways as a sum of consecutive naturals, for example, 166961 + ... + 167087.

Almost surely, 2^21212048 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 21212048, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24665088).

21212048 is an abundant number, since it is smaller than the sum of its proper divisors (28118128).

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

21212048 is a wasteful number, since it uses less digits than its factorization.

21212048 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 232 (or 226 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 20.

The square root of 21212048 is about 4605.6539166550. The cubic root of 21212048 is about 276.8179195857.

It can be divided in two parts, 2121204 and 8, that added together give a palindrome (2121212).

The spelling of 21212048 in words is "twenty-one million, two hundred twelve thousand, forty-eight".