21718106 has 8 divisors (see below), whose sum is σ = 32913300. Its totient is φ = 10747008.

The previous prime is 21718087. The next prime is 21718133. The reversal of 21718106 is 60181712.

It can be written as a sum of positive squares in 2 ways, for example, as 18567481 + 3150625 = 4309^2 + 1775^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×21718106² = 943352256454472, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 55781 + ... + 56168.

Almost surely, 2^21718106 is an apocalyptic number.

21718106 is a deficient number, since it is larger than the sum of its proper divisors (11195194).

21718106 is a wasteful number, since it uses less digits than its factorization.

21718106 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 112048.

The product of its (nonzero) digits is 672, while the sum is 26.

The square root of 21718106 is about 4660.2688763633. The cubic root of 21718106 is about 279.0019997887.

Adding to 21718106 its reverse (60181712), we get a palindrome (81899818).

The spelling of 21718106 in words is "twenty-one million, seven hundred eighteen thousand, one hundred six".