21115032281 has 8 divisors (see below), whose sum is σ = 24133284864. Its totient is φ = 18097234560.

The previous prime is 21115032233. The next prime is 21115032283. The reversal of 21115032281 is 18223051112.

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 21115032281 - 2¹⁰ = 21115031257 is a prime.

It is a super-2 number, since 2×21115032281² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21115032281.

It is not an unprimeable number, because it can be changed into a prime (21115032283) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7640 + ... + 205641.

It is an arithmetic number, because the mean of its divisors is an integer number (3016660608).

Almost surely, 2^21115032281 is an apocalyptic number.

It is an amenable number.

21115032281 is a deficient number, since it is larger than the sum of its proper divisors (3018252583).

21115032281 is a wasteful number, since it uses less digits than its factorization.

21115032281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 227431.

The product of its (nonzero) digits is 960, while the sum is 26.

Adding to 21115032281 its reverse (18223051112), we get a palindrome (39338083393).

The spelling of 21115032281 in words is "twenty-one billion, one hundred fifteen million, thirty-two thousand, two hundred eighty-one".