21366311424 has 40 divisors (see below), whose sum is σ = 56921193120. Its totient is φ = 7122103296.

The previous prime is 21366311419. The next prime is 21366311441. The reversal of 21366311424 is 42411366312.

It is a happy number.

It is a nude number because it is divisible by every one of its digits.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6953644 + ... + 6956715.

It is an arithmetic number, because the mean of its divisors is an integer number (1423029828).

Almost surely, 2^21366311424 is an apocalyptic number.

21366311424 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21366311424 is an abundant number, since it is smaller than the sum of its proper divisors (35554881696).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21366311424 is an equidigital number, since it uses as much as digits as its factorization.

21366311424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13910380 (or 13910364 counting only the distinct ones).

The product of its digits is 20736, while the sum is 33.

Adding to 21366311424 its reverse (42411366312), we get a palindrome (63777677736).

The spelling of 21366311424 in words is "twenty-one billion, three hundred sixty-six million, three hundred eleven thousand, four hundred twenty-four".