21602016 has 72 divisors (see below), whose sum is σ = 62093304. Its totient is φ = 7123200.

The previous prime is 21602003. The next prime is 21602029. The reversal of 21602016 is 61020612.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21602003) and next prime (21602029).

It is a tau number, because it is divible by the number of its divisors (72).

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

It is a self number, because there is not a number n which added to its sum of digits gives 21602016.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 30466 + ... + 31166.

It is an arithmetic number, because the mean of its divisors is an integer number (862407).

Almost surely, 2^21602016 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 21602016, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31046652).

21602016 is an abundant number, since it is smaller than the sum of its proper divisors (40491288).

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

21602016 is a wasteful number, since it uses less digits than its factorization.

21602016 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 824 (or 813 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 21602016 is about 4647.7968974558. The cubic root of 21602016 is about 278.5039940464.

Adding to 21602016 its reverse (61020612), we get a palindrome (82622628).

The spelling of 21602016 in words is "twenty-one million, six hundred two thousand, sixteen".