21166368 has 96 divisors (see below), whose sum is σ = 58605120. Its totient is φ = 6681600.

The previous prime is 21166367. The next prime is 21166381. The reversal of 21166368 is 86366112.

It is a tau number, because it is divible by the number of its divisors (96).

It is a super-2 number, since 2×21166368² = 896030268622848, which contains 22 as substring.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21166367) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 209518 + ... + 209618.

It is an arithmetic number, because the mean of its divisors is an integer number (610470).

Almost surely, 2^21166368 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 21166368, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29302560).

21166368 is an abundant number, since it is smaller than the sum of its proper divisors (37438752).

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

21166368 is a wasteful number, since it uses less digits than its factorization.

21166368 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 210 (or 202 counting only the distinct ones).

The product of its digits is 10368, while the sum is 33.

The square root of 21166368 is about 4600.6921218443. The cubic root of 21166368 is about 276.6190682780.

The spelling of 21166368 in words is "twenty-one million, one hundred sixty-six thousand, three hundred sixty-eight".