21466789865 has 8 divisors (see below), whose sum is σ = 27275450760. Its totient is φ = 16163229952.

The previous prime is 21466789849. The next prime is 21466789867. The reversal of 21466789865 is 56898766412.

It can be written as a sum of positive squares in 4 ways, for example, as 6673419481 + 14793370384 = 81691^2 + 121628^2 .

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 21466789865 - 2⁴ = 21466789849 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21466789798 and 21466789807.

It is not an unprimeable number, because it can be changed into a prime (21466789867) 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, 126275150 + ... + 126275319.

It is an arithmetic number, because the mean of its divisors is an integer number (3409431345).

Almost surely, 2^21466789865 is an apocalyptic number.

It is an amenable number.

21466789865 is a deficient number, since it is larger than the sum of its proper divisors (5808660895).

21466789865 is a wasteful number, since it uses less digits than its factorization.

21466789865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 252550491.

The product of its digits is 34836480, while the sum is 62.

The spelling of 21466789865 in words is "twenty-one billion, four hundred sixty-six million, seven hundred eighty-nine thousand, eight hundred sixty-five".