21531541205331 has 24 divisors (see below), whose sum is σ = 31173828403536. Its totient is φ = 14320802695680.

The previous prime is 21531541205309. The next prime is 21531541205347. The reversal of 21531541205331 is 13350214513512.

It is a happy number.

21531541205331 is a `hidden beast` number, since 2 + 1 + 5 + 31 + 541 + 2 + 0 + 53 + 31 = 666.

It is not a de Polignac number, because 21531541205331 - 2⁹ = 21531541204819 is a prime.

It is a super-2 number, since 2×21531541205331² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21531541205131) 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, 207155431 + ... + 207259343.

It is an arithmetic number, because the mean of its divisors is an integer number (1298909516814).

Almost surely, 2^{21531541205331} is an apocalyptic number.

21531541205331 is a deficient number, since it is larger than the sum of its proper divisors (9642287198205).

21531541205331 is a wasteful number, since it uses less digits than its factorization.

21531541205331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 157523 (or 157520 counting only the distinct ones).

The product of its (nonzero) digits is 54000, while the sum is 36.

Adding to 21531541205331 its reverse (13350214513512), we get a palindrome (34881755718843).

The spelling of 21531541205331 in words is "twenty-one trillion, five hundred thirty-one billion, five hundred forty-one million, two hundred five thousand, three hundred thirty-one".