21168863441 has 16 divisors (see below), whose sum is σ = 24259132800. Its totient is φ = 18284133120.

The previous prime is 21168863431. The next prime is 21168863449. The reversal of 21168863441 is 14436886112.

It is a de Polignac number, because none of the positive numbers 2^k-21168863441 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21168863392 and 21168863401.

It is not an unprimeable number, because it can be changed into a prime (21168863449) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 243080 + ... + 318473.

It is an arithmetic number, because the mean of its divisors is an integer number (1516195800).

Almost surely, 2^21168863441 is an apocalyptic number.

It is an amenable number.

21168863441 is a deficient number, since it is larger than the sum of its proper divisors (3090269359).

21168863441 is a wasteful number, since it uses less digits than its factorization.

21168863441 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 561736.

The product of its digits is 221184, while the sum is 44.

The spelling of 21168863441 in words is "twenty-one billion, one hundred sixty-eight million, eight hundred sixty-three thousand, four hundred forty-one".