21833353833521 has 4 divisors (see below), whose sum is σ = 21865603987572. Its totient is φ = 21801103679472.

The previous prime is 21833353833517. The next prime is 21833353833539. The reversal of 21833353833521 is 12533835333812.

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 14594967152896 + 7238386680625 = 3820336^2 + 2690425^2 .

It is a cyclic number.

It is not a de Polignac number, because 21833353833521 - 2² = 21833353833517 is a prime.

It is a super-2 number, since 2×21833353833521² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21833353833521.

It is not an unprimeable number, because it can be changed into a prime (21833353883521) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16125076010 + ... + 16125077363.

It is an arithmetic number, because the mean of its divisors is an integer number (5466400996893).

Almost surely, 2^{21833353833521} is an apocalyptic number.

It is an amenable number.

21833353833521 is a deficient number, since it is larger than the sum of its proper divisors (32250154051).

21833353833521 is an equidigital number, since it uses as much as digits as its factorization.

21833353833521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32250154050.

The product of its digits is 4665600, while the sum is 50.

The spelling of 21833353833521 in words is "twenty-one trillion, eight hundred thirty-three billion, three hundred fifty-three million, eight hundred thirty-three thousand, five hundred twenty-one".