21675718 has 4 divisors (see below), whose sum is σ = 32513580. Its totient is φ = 10837858.

The previous prime is 21675701. The next prime is 21675721. The reversal of 21675718 is 81757612.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5418928 + ... + 5418931.

It is an arithmetic number, because the mean of its divisors is an integer number (8128395).

Almost surely, 2^21675718 is an apocalyptic number.

21675718 is a deficient number, since it is larger than the sum of its proper divisors (10837862).

21675718 is a wasteful number, since it uses less digits than its factorization.

21675718 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10837861.

The product of its digits is 23520, while the sum is 37.

The square root of 21675718 is about 4655.7188488997. The cubic root of 21675718 is about 278.8203688631.

The spelling of 21675718 in words is "twenty-one million, six hundred seventy-five thousand, seven hundred eighteen".