21404430304416 has 72 divisors (see below), whose sum is σ = 61427278572660. Its totient is φ = 7069353117696.

The previous prime is 21404430304399. The next prime is 21404430304441. The reversal of 21404430304416 is 61440303440412.

21404430304416 is a `hidden beast` number, since 2 + 140 + 4 + 43 + 0 + 30 + 441 + 6 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 21315026912400 + 89403392016 = 4616820^2 + 299004^2 .

It is a tau number, because it is divible by the number of its divisors (72).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 340890345 + ... + 340953128.

Almost surely, 2^{21404430304416} is an apocalyptic number.

It is an amenable number.

21404430304416 is an abundant number, since it is smaller than the sum of its proper divisors (40022848268244).

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

21404430304416 is a wasteful number, since it uses less digits than its factorization.

21404430304416 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 681843598 (or 681843587 counting only the distinct ones).

The product of its (nonzero) digits is 110592, while the sum is 36.

Adding to 21404430304416 its reverse (61440303440412), we get a palindrome (82844733744828).

The spelling of 21404430304416 in words is "twenty-one trillion, four hundred four billion, four hundred thirty million, three hundred four thousand, four hundred sixteen".