21690384011 has 4 divisors (see below), whose sum is σ = 21694112232. Its totient is φ = 21686655792.

The previous prime is 21690384007. The next prime is 21690384029. The reversal of 21690384011 is 11048309612.

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 21690384011 - 2² = 21690384007 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21690384061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1855370 + ... + 1867023.

It is an arithmetic number, because the mean of its divisors is an integer number (5423528058).

Almost surely, 2^21690384011 is an apocalyptic number.

21690384011 is a deficient number, since it is larger than the sum of its proper divisors (3728221).

21690384011 is an equidigital number, since it uses as much as digits as its factorization.

21690384011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3728220.

The product of its (nonzero) digits is 10368, while the sum is 35.

The spelling of 21690384011 in words is "twenty-one billion, six hundred ninety million, three hundred eighty-four thousand, eleven".