21066552 has 96 divisors (see below), whose sum is σ = 62506080. Its totient is φ = 6370560.

The previous prime is 21066527. The next prime is 21066581. The reversal of 21066552 is 25566012.

21066552 is a `hidden beast` number, since 2 + 1 + 0 + 6 + 655 + 2 = 666.

It is a super-2 number, since 2×21066552² = 887599226337408, which contains 22 as substring.

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 23 ways as a sum of consecutive naturals, for example, 66298 + ... + 66614.

It is an arithmetic number, because the mean of its divisors is an integer number (651105).

Almost surely, 2^21066552 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 21066552, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31253040).

21066552 is an abundant number, since it is smaller than the sum of its proper divisors (41439528).

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

21066552 is a wasteful number, since it uses less digits than its factorization.

21066552 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 413 (or 406 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 27.

The square root of 21066552 is about 4589.8313694514. The cubic root of 21066552 is about 276.1835577944.

The spelling of 21066552 in words is "twenty-one million, sixty-six thousand, five hundred fifty-two".