21306968081 has 8 divisors (see below), whose sum is σ = 25136331264. Its totient is φ = 17673982560.

The previous prime is 21306968063. The next prime is 21306968107. The reversal of 21306968081 is 18086960312.

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 21306968081 - 2⁶ = 21306968017 is a prime.

It is a super-2 number, since 2×21306968081² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21306968021) 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, 49094180 + ... + 49094613.

It is an arithmetic number, because the mean of its divisors is an integer number (3142041408).

Almost surely, 2^21306968081 is an apocalyptic number.

It is an amenable number.

21306968081 is a deficient number, since it is larger than the sum of its proper divisors (3829363183).

21306968081 is an equidigital number, since it uses as much as digits as its factorization.

21306968081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 98188831.

The product of its (nonzero) digits is 124416, while the sum is 44.

The spelling of 21306968081 in words is "twenty-one billion, three hundred six million, nine hundred sixty-eight thousand, eighty-one".