21426552 has 128 divisors (see below), whose sum is σ = 70041600. Its totient is φ = 5940864.

The previous prime is 21426541. The next prime is 21426553. The reversal of 21426552 is 25562412.

21426552 is a `hidden beast` number, since 2 + 1 + 4 + 2 + 655 + 2 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21426553) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 55753 + ... + 56135.

It is an arithmetic number, because the mean of its divisors is an integer number (547200).

Almost surely, 2^21426552 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 21426552, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35020800).

21426552 is an abundant number, since it is smaller than the sum of its proper divisors (48615048).

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

21426552 is a wasteful number, since it uses less digits than its factorization.

21426552 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 442 (or 432 counting only the distinct ones).

The product of its digits is 4800, while the sum is 27.

The square root of 21426552 is about 4628.8823705080. The cubic root of 21426552 is about 277.7478866088.

Adding to 21426552 its reverse (25562412), we get a palindrome (46988964).

The spelling of 21426552 in words is "twenty-one million, four hundred twenty-six thousand, five hundred fifty-two".