21695867 has 4 divisors (see below), whose sum is σ = 21705720. Its totient is φ = 21686016.

The previous prime is 21695837. The next prime is 21695879. The reversal of 21695867 is 76859612.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 21695867 - 2¹⁰ = 21694843 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21695837) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 59 + ... + 6587.

It is an arithmetic number, because the mean of its divisors is an integer number (5426430).

Almost surely, 2^21695867 is an apocalyptic number.

21695867 is a deficient number, since it is larger than the sum of its proper divisors (9853).

21695867 is an equidigital number, since it uses as much as digits as its factorization.

21695867 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9852.

The product of its digits is 181440, while the sum is 44.

The square root of 21695867 is about 4657.8822441105. The cubic root of 21695867 is about 278.9067360408.

The spelling of 21695867 in words is "twenty-one million, six hundred ninety-five thousand, eight hundred sixty-seven".