21404333400400 has 60 divisors (see below), whose sum is σ = 51499870155612. Its totient is φ = 8549086673920.

The previous prime is 21404333400397. The next prime is 21404333400409. The reversal of 21404333400400 is 400433340412.

It can be written as a sum of positive squares in 6 ways, for example, as 101271605824 + 21303061794576 = 318232^2 + 4615524^2 .

It is a super-3 number, since 3×21404333400400³ (a number of 41 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21404333400409) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 39249757 + ... + 39791356.

Almost surely, 2^{21404333400400} is an apocalyptic number.

21404333400400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21404333400400 is an abundant number, since it is smaller than the sum of its proper divisors (30095536755212).

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

21404333400400 is a wasteful number, since it uses less digits than its factorization.

21404333400400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79041808 (or 79041797 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 28.

Adding to 21404333400400 its reverse (400433340412), we get a palindrome (21804766740812).

The spelling of 21404333400400 in words is "twenty-one trillion, four hundred four billion, three hundred thirty-three million, four hundred thousand, four hundred".