21411212165 has 8 divisors (see below), whose sum is σ = 29363948160. Its totient is φ = 14681974032.

The previous prime is 21411212149. The next prime is 21411212171. The reversal of 21411212165 is 56121211412.

It is a happy number.

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 21411212165 - 2⁴ = 21411212149 is a prime.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 305874425 + ... + 305874494.

It is an arithmetic number, because the mean of its divisors is an integer number (3670493520).

Almost surely, 2^21411212165 is an apocalyptic number.

It is an amenable number.

21411212165 is a deficient number, since it is larger than the sum of its proper divisors (7952735995).

21411212165 is an equidigital number, since it uses as much as digits as its factorization.

21411212165 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 611748931.

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

Adding to 21411212165 its reverse (56121211412), we get a palindrome (77532423577).

The spelling of 21411212165 in words is "twenty-one billion, four hundred eleven million, two hundred twelve thousand, one hundred sixty-five".