21164360 has 64 divisors (see below), whose sum is σ = 54933120. Its totient is φ = 7188480.

The previous prime is 21164357. The next prime is 21164401. The reversal of 21164360 is 6346112.

21164360 = 378² + 379² + ... + 489².

It is a happy 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, 36392 + ... + 36968.

It is an arithmetic number, because the mean of its divisors is an integer number (858330).

Almost surely, 2^21164360 is an apocalyptic number.

21164360 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 21164360, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27466560).

21164360 is an abundant number, since it is smaller than the sum of its proper divisors (33768760).

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

21164360 is a wasteful number, since it uses less digits than its factorization.

21164360 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 726 (or 722 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 21164360 is about 4600.4738886336. The cubic root of 21164360 is about 276.6103206167.

The spelling of 21164360 in words is "twenty-one million, one hundred sixty-four thousand, three hundred sixty".