21312404011 has 4 divisors (see below), whose sum is σ = 21312913752. Its totient is φ = 21311894272.

The previous prime is 21312403999. The next prime is 21312404021. The reversal of 21312404011 is 11040421312.

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 21312404011 - 2⁵ = 21312403979 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21312404011.

It is not an unprimeable number, because it can be changed into a prime (21312404021) 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, 185941 + ... + 277846.

It is an arithmetic number, because the mean of its divisors is an integer number (5328228438).

Almost surely, 2^21312404011 is an apocalyptic number.

21312404011 is a deficient number, since it is larger than the sum of its proper divisors (509741).

21312404011 is an equidigital number, since it uses as much as digits as its factorization.

21312404011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 509740.

The product of its (nonzero) digits is 192, while the sum is 19.

Adding to 21312404011 its reverse (11040421312), we get a palindrome (32352825323).

The spelling of 21312404011 in words is "twenty-one billion, three hundred twelve million, four hundred four thousand, eleven".