21171360 has 96 divisors (see below), whose sum is σ = 76228992. Its totient is φ = 4838400.

The previous prime is 21171349. The next prime is 21171361. The reversal of 21171360 is 6317112.

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

It is a Harshad number since it is a multiple of its sum of digits (21).

It is not an unprimeable number, because it can be changed into a prime (21171361) 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, 210 + ... + 6510.

It is an arithmetic number, because the mean of its divisors is an integer number (794052).

Almost surely, 2^21171360 is an apocalyptic number.

21171360 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21171360, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38114496).

21171360 is an abundant number, since it is smaller than the sum of its proper divisors (55057632).

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

21171360 is a wasteful number, since it uses less digits than its factorization.

21171360 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6326 (or 6318 counting only the distinct ones).

The product of its (nonzero) digits is 252, while the sum is 21.

The square root of 21171360 is about 4601.2346169262. The cubic root of 21171360 is about 276.6408130549.

Adding to 21171360 its reverse (6317112), we get a palindrome (27488472).

The spelling of 21171360 in words is "twenty-one million, one hundred seventy-one thousand, three hundred sixty".