21443235408 has 80 divisors (see below), whose sum is σ = 70342898560. Its totient is φ = 6126637824.

The previous prime is 21443235367. The next prime is 21443235421. The reversal of 21443235408 is 80453234412.

21443235408 is a `hidden beast` number, since 2 + 14 + 4 + 3 + 235 + 408 = 666.

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

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 3542485 + ... + 3548532.

It is an arithmetic number, because the mean of its divisors is an integer number (879286232).

Almost surely, 2^21443235408 is an apocalyptic number.

21443235408 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21443235408 is an abundant number, since it is smaller than the sum of its proper divisors (48899663152).

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

21443235408 is a wasteful number, since it uses less digits than its factorization.

21443235408 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7091041 (or 7091029 counting only the distinct ones).

The product of its (nonzero) digits is 92160, while the sum is 36.

The spelling of 21443235408 in words is "twenty-one billion, four hundred forty-three million, two hundred thirty-five thousand, four hundred eight".