21454435444 has 24 divisors (see below), whose sum is σ = 40452559560. Its totient is φ = 9897345024.

The previous prime is 21454435369. The next prime is 21454435463. The reversal of 21454435444 is 44453445412.

It can be written as a sum of positive squares in 4 ways, for example, as 1066022500 + 20388412944 = 32650^2 + 142788^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21454435397 and 21454435406.

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 7 ways as a sum of consecutive naturals, for example, 13812 + ... + 207604.

It is an arithmetic number, because the mean of its divisors is an integer number (1685523315).

Almost surely, 2^21454435444 is an apocalyptic number.

It is an amenable number.

21454435444 is a deficient number, since it is larger than the sum of its proper divisors (18998124116).

21454435444 is a wasteful number, since it uses less digits than its factorization.

21454435444 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 195939 (or 195937 counting only the distinct ones).

The product of its digits is 614400, while the sum is 40.

The spelling of 21454435444 in words is "twenty-one billion, four hundred fifty-four million, four hundred thirty-five thousand, four hundred forty-four".