21675855 has 8 divisors (see below), whose sum is σ = 34681392. Its totient is φ = 11560448.

The previous prime is 21675853. The next prime is 21675869. The reversal of 21675855 is 55857612.

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

It is a cyclic number.

It is not a de Polignac number, because 21675855 - 2¹ = 21675853 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21675853) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 722514 + ... + 722543.

It is an arithmetic number, because the mean of its divisors is an integer number (4335174).

Almost surely, 2^21675855 is an apocalyptic number.

21675855 is a deficient number, since it is larger than the sum of its proper divisors (13005537).

21675855 is a wasteful number, since it uses less digits than its factorization.

21675855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1445065.

The product of its digits is 84000, while the sum is 39.

The square root of 21675855 is about 4655.7335619642. The cubic root of 21675855 is about 278.8209562841.

The spelling of 21675855 in words is "twenty-one million, six hundred seventy-five thousand, eight hundred fifty-five".