21531838667539 has 8 divisors (see below), whose sum is σ = 21541523889600. Its totient is φ = 21522153959400.

The previous prime is 21531838667519. The next prime is 21531838667569. The reversal of 21531838667539 is 93576683813512.

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 21531838667539 - 2⁷ = 21531838667411 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21531838667519) 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, 101607684 + ... + 101819374.

It is an arithmetic number, because the mean of its divisors is an integer number (2692690486200).

Almost surely, 2^{21531838667539} is an apocalyptic number.

21531838667539 is a deficient number, since it is larger than the sum of its proper divisors (9685222061).

21531838667539 is a wasteful number, since it uses less digits than its factorization.

21531838667539 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 256961.

The product of its digits is 195955200, while the sum is 67.

The spelling of 21531838667539 in words is "twenty-one trillion, five hundred thirty-one billion, eight hundred thirty-eight million, six hundred sixty-seven thousand, five hundred thirty-nine".