21108602 has 4 divisors (see below), whose sum is σ = 31662906. Its totient is φ = 10554300.

The previous prime is 21108587. The next prime is 21108631. The reversal of 21108602 is 20680112.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 20421361 + 687241 = 4519^2 + 829^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5277149 + ... + 5277152.

Almost surely, 2^21108602 is an apocalyptic number.

21108602 is a deficient number, since it is larger than the sum of its proper divisors (10554304).

21108602 is a wasteful number, since it uses less digits than its factorization.

21108602 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10554303.

The product of its (nonzero) digits is 192, while the sum is 20.

The square root of 21108602 is about 4594.4098641719. The cubic root of 21108602 is about 276.3671948712.

Adding to 21108602 its reverse (20680112), we get a palindrome (41788714).

The spelling of 21108602 in words is "twenty-one million, one hundred eight thousand, six hundred two".