21013168 has 80 divisors (see below), whose sum is σ = 48211200. Its totient is φ = 8771840.

The previous prime is 21013159. The next prime is 21013177. The reversal of 21013168 is 86131012.

It is an interprime number because it is at equal distance from previous prime (21013159) and next prime (21013177).

It is a Harshad number since it is a multiple of its sum of digits (22).

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, 117303 + ... + 117481.

It is an arithmetic number, because the mean of its divisors is an integer number (602640).

Almost surely, 2^21013168 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 21013168, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24105600).

21013168 is an abundant number, since it is smaller than the sum of its proper divisors (27198032).

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

21013168 is a wasteful number, since it uses less digits than its factorization.

21013168 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 250 (or 244 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 22.

The square root of 21013168 is about 4584.0122163886. The cubic root of 21013168 is about 275.9500714838.

The spelling of 21013168 in words is "twenty-one million, thirteen thousand, one hundred sixty-eight".