21531231522 has 48 divisors (see below), whose sum is σ = 47458187712. Its totient is φ = 7053537120.

The previous prime is 21531231517. The next prime is 21531231529. The reversal of 21531231522 is 22513213512.

21531231522 is a `hidden beast` number, since 2 + 15 + 3 + 123 + 1 + 522 = 666.

It is not an unprimeable number, because it can be changed into a prime (21531231529) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 378553 + ... + 431699.

It is an arithmetic number, because the mean of its divisors is an integer number (988712244).

Almost surely, 2^21531231522 is an apocalyptic number.

21531231522 is an abundant number, since it is smaller than the sum of its proper divisors (25926956190).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21531231522 is a wasteful number, since it uses less digits than its factorization.

21531231522 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53543 (or 53540 counting only the distinct ones).

The product of its digits is 3600, while the sum is 27.

The spelling of 21531231522 in words is "twenty-one billion, five hundred thirty-one million, two hundred thirty-one thousand, five hundred twenty-two".