21016602 has 24 divisors (see below), whose sum is σ = 46009236. Its totient is φ = 6932736.

The previous prime is 21016601. The next prime is 21016609. The reversal of 21016602 is 20661012.

It is a happy number.

21016602 is a `hidden beast` number, since 2 + 1 + 0 + 1 + 660 + 2 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 18224361 + 2792241 = 4269^2 + 1671^2 .

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

It is not an unprimeable number, because it can be changed into a prime (21016601) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4273 + ... + 7764.

Almost surely, 2^21016602 is an apocalyptic number.

21016602 is an abundant number, since it is smaller than the sum of its proper divisors (24992634).

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

21016602 is a wasteful number, since it uses less digits than its factorization.

21016602 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12142 (or 12139 counting only the distinct ones).

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

The square root of 21016602 is about 4584.3867637886. The cubic root of 21016602 is about 275.9651027081.

Adding to 21016602 its reverse (20661012), we get a palindrome (41677614).

The spelling of 21016602 in words is "twenty-one million, sixteen thousand, six hundred two".