21533531340213 has 24 divisors (see below), whose sum is σ = 31112940456000. Its totient is φ = 14351557058304.

The previous prime is 21533531340143. The next prime is 21533531340221. The reversal of 21533531340213 is 31204313533512.

21533531340213 is a `hidden beast` number, since 2 + 1 + 5 + 335 + 313 + 4 + 0 + 2 + 1 + 3 = 666.

It is not a de Polignac number, because 21533531340213 - 2¹² = 21533531336117 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21533531340913) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 688858978 + ... + 688890236.

It is an arithmetic number, because the mean of its divisors is an integer number (1296372519000).

Almost surely, 2^{21533531340213} is an apocalyptic number.

It is an amenable number.

21533531340213 is a deficient number, since it is larger than the sum of its proper divisors (9579409115787).

21533531340213 is a wasteful number, since it uses less digits than its factorization.

21533531340213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50841 (or 50838 counting only the distinct ones).

The product of its (nonzero) digits is 97200, while the sum is 36.

Adding to 21533531340213 its reverse (31204313533512), we get a palindrome (52737844873725).

The spelling of 21533531340213 in words is "twenty-one trillion, five hundred thirty-three billion, five hundred thirty-one million, three hundred forty thousand, two hundred thirteen".