21170214 has 64 divisors (see below), whose sum is σ = 51710400. Its totient is φ = 6379776.

The previous prime is 21170213. The next prime is 21170221. The reversal of 21170214 is 41207112.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21170213) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 36922 + ... + 37490.

It is an arithmetic number, because the mean of its divisors is an integer number (807975).

Almost surely, 2^21170214 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21170214, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25855200).

21170214 is an abundant number, since it is smaller than the sum of its proper divisors (30540186).

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

21170214 is a wasteful number, since it uses less digits than its factorization.

21170214 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 646 (or 640 counting only the distinct ones).

The product of its (nonzero) digits is 112, while the sum is 18.

The square root of 21170214 is about 4601.1100834473. The cubic root of 21170214 is about 276.6358214673.

Adding to 21170214 its reverse (41207112), we get a palindrome (62377326).

It can be divided in two parts, 2117021 and 4, that added together give a square (2117025 = 1455²).

The spelling of 21170214 in words is "twenty-one million, one hundred seventy thousand, two hundred fourteen".