21159531121 has 8 divisors (see below), whose sum is σ = 21229040000. Its totient is φ = 21090073680.

The previous prime is 21159531119. The next prime is 21159531167. The reversal of 21159531121 is 12113595112.

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 21159531121 - 2¹ = 21159531119 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21159531101) 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, 920830 + ... + 943528.

It is an arithmetic number, because the mean of its divisors is an integer number (2653630000).

Almost surely, 2^21159531121 is an apocalyptic number.

It is an amenable number.

21159531121 is a deficient number, since it is larger than the sum of its proper divisors (69508879).

21159531121 is a wasteful number, since it uses less digits than its factorization.

21159531121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25719.

The product of its digits is 2700, while the sum is 31.

The spelling of 21159531121 in words is "twenty-one billion, one hundred fifty-nine million, five hundred thirty-one thousand, one hundred twenty-one".