21102552 has 64 divisors (see below), whose sum is σ = 59097600. Its totient is φ = 6976800.

The previous prime is 21102547. The next prime is 21102581. The reversal of 21102552 is 25520112.

21102552 is a `hidden beast` number, since 2 + 110 + 2 + 552 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 32293 + ... + 32939.

It is an arithmetic number, because the mean of its divisors is an integer number (923400).

Almost surely, 2^21102552 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 21102552, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29548800).

21102552 is an abundant number, since it is smaller than the sum of its proper divisors (37995048).

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

21102552 is a wasteful number, since it uses less digits than its factorization.

21102552 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 813 (or 803 counting only the distinct ones).

The product of its (nonzero) digits is 200, while the sum is 18.

The square root of 21102552 is about 4593.7514081630. The cubic root of 21102552 is about 276.3407888703.

Adding to 21102552 its reverse (25520112), we get a palindrome (46622664).

The spelling of 21102552 in words is "twenty-one million, one hundred two thousand, five hundred fifty-two".