21223737055445 has 4 divisors (see below), whose sum is σ = 25468484466540. Its totient is φ = 16978989644352.

The previous prime is 21223737055441. The next prime is 21223737055457. The reversal of 21223737055445 is 54455073732212.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 15639485993041 + 5584251062404 = 3954679^2 + 2363102^2 .

It is a cyclic number.

It is not a de Polignac number, because 21223737055445 - 2² = 21223737055441 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21223737055393 and 21223737055402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21223737055441) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 2122373705540 + ... + 2122373705549.

It is an arithmetic number, because the mean of its divisors is an integer number (6367121116635).

Almost surely, 2^{21223737055445} is an apocalyptic number.

It is an amenable number.

21223737055445 is a deficient number, since it is larger than the sum of its proper divisors (4244747411095).

21223737055445 is an equidigital number, since it uses as much as digits as its factorization.

21223737055445 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4244747411094.

The product of its (nonzero) digits is 7056000, while the sum is 50.

The spelling of 21223737055445 in words is "twenty-one trillion, two hundred twenty-three billion, seven hundred thirty-seven million, fifty-five thousand, four hundred forty-five".