21708162 has 64 divisors (see below), whose sum is σ = 55891200. Its totient is φ = 6193584.

The previous prime is 21708157. The next prime is 21708187. The reversal of 21708162 is 26180712.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 30264 + ... + 30972.

It is an arithmetic number, because the mean of its divisors is an integer number (873300).

Almost surely, 2^21708162 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21708162, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27945600).

21708162 is an abundant number, since it is smaller than the sum of its proper divisors (34183038).

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

21708162 is an frugal number, since it uses more digits than its factorization.

21708162 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 739 (or 721 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 27.

The square root of 21708162 is about 4659.2018629804. The cubic root of 21708162 is about 278.9594113692.

Adding to 21708162 its reverse (26180712), we get a palindrome (47888874).

The spelling of 21708162 in words is "twenty-one million, seven hundred eight thousand, one hundred sixty-two".