22121061665 has 8 divisors (see below), whose sum is σ = 26546558568. Its totient is φ = 17695992960.

The previous prime is 22121061653. The next prime is 22121061701. The reversal of 22121061665 is 56616012122.

It can be written as a sum of positive squares in 4 ways, for example, as 3125824 + 22117935841 = 1768^2 + 148721^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-22121061665 is a prime.

It is a Duffinian 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, 20405 + ... + 211325.

It is an arithmetic number, because the mean of its divisors is an integer number (3318319821).

Almost surely, 2^22121061665 is an apocalyptic number.

It is an amenable number.

22121061665 is a deficient number, since it is larger than the sum of its proper divisors (4425496903).

22121061665 is a wasteful number, since it uses less digits than its factorization.

22121061665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 214099.

The product of its (nonzero) digits is 8640, while the sum is 32.

Adding to 22121061665 its reverse (56616012122), we get a palindrome (78737073787).

The spelling of 22121061665 in words is "twenty-two billion, one hundred twenty-one million, sixty-one thousand, six hundred sixty-five".