21531533020013 has 8 divisors (see below), whose sum is σ = 21737874267648. Its totient is φ = 21326172016464.

The previous prime is 21531533019961. The next prime is 21531533020069. The reversal of 21531533020013 is 31002033513512.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21531533020013 - 2²⁶ = 21531465911149 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21531533020213) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 245016881 + ... + 245104742.

It is an arithmetic number, because the mean of its divisors is an integer number (2717234283456).

Almost surely, 2^{21531533020013} is an apocalyptic number.

It is an amenable number.

21531533020013 is a deficient number, since it is larger than the sum of its proper divisors (206341247635).

21531533020013 is a wasteful number, since it uses less digits than its factorization.

21531533020013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 490122043.

The product of its (nonzero) digits is 8100, while the sum is 29.

Adding to 21531533020013 its reverse (31002033513512), we get a palindrome (52533566533525).

The spelling of 21531533020013 in words is "twenty-one trillion, five hundred thirty-one billion, five hundred thirty-three million, twenty thousand, thirteen".