21444687355 has 64 divisors (see below), whose sum is σ = 32505355008. Its totient is φ = 13217955840.

The previous prime is 21444687331. The next prime is 21444687371. The reversal of 21444687355 is 55378644412.

It is not a de Polignac number, because 21444687355 - 2¹¹ = 21444685307 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21444687299 and 21444687308.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 18598459 + ... + 18599611.

It is an arithmetic number, because the mean of its divisors is an integer number (507896172).

Almost surely, 2^21444687355 is an apocalyptic number.

21444687355 is a deficient number, since it is larger than the sum of its proper divisors (11060667653).

21444687355 is a wasteful number, since it uses less digits than its factorization.

21444687355 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2216.

The product of its digits is 3225600, while the sum is 49.

The spelling of 21444687355 in words is "twenty-one billion, four hundred forty-four million, six hundred eighty-seven thousand, three hundred fifty-five".