21696835 has 4 divisors (see below), whose sum is σ = 26036208. Its totient is φ = 17357464.

The previous prime is 21696833. The next prime is 21696839. The reversal of 21696835 is 53869612.

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

It is a cyclic number.

It is not a de Polignac number, because 21696835 - 2¹ = 21696833 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21696833) 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, 2169679 + ... + 2169688.

It is an arithmetic number, because the mean of its divisors is an integer number (6509052).

Almost surely, 2^21696835 is an apocalyptic number.

21696835 is a deficient number, since it is larger than the sum of its proper divisors (4339373).

21696835 is an equidigital number, since it uses as much as digits as its factorization.

21696835 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4339372.

The product of its digits is 77760, while the sum is 40.

The square root of 21696835 is about 4657.9861528347. The cubic root of 21696835 is about 278.9108839537.

The spelling of 21696835 in words is "twenty-one million, six hundred ninety-six thousand, eight hundred thirty-five".