21404420324 has 12 divisors (see below), whose sum is σ = 42808840704. Its totient is φ = 9173322984.

The previous prime is 21404420321. The next prime is 21404420327. The reversal of 21404420324 is 42302440412.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21404420321) and next prime (21404420327).

21404420324 is an admirable number.

It is a junction number, because it is equal to n+sod(n) for n = 21404420293 and 21404420302.

It is not an unprimeable number, because it can be changed into a prime (21404420321) 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, 382221764 + ... + 382221819.

It is an arithmetic number, because the mean of its divisors is an integer number (3567403392).

Almost surely, 2^21404420324 is an apocalyptic number.

It is an amenable number.

21404420324 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21404420324 is a wasteful number, since it uses less digits than its factorization.

21404420324 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 764443594 (or 764443592 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 26.

Adding to 21404420324 its reverse (42302440412), we get a palindrome (63706860736).

The spelling of 21404420324 in words is "twenty-one billion, four hundred four million, four hundred twenty thousand, three hundred twenty-four".