21574221065 has 16 divisors (see below), whose sum is σ = 26750876160. Its totient is φ = 16685948160.

The previous prime is 21574221047. The next prime is 21574221089. The reversal of 21574221065 is 56012247512.

It is not a de Polignac number, because 21574221065 - 2¹⁸ = 21573958921 is a prime.

It is a super-2 number, since 2×21574221065² (a number of 21 digits) contains 22 as substring.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 87422 + ... + 225368.

It is an arithmetic number, because the mean of its divisors is an integer number (1671929760).

Almost surely, 2^21574221065 is an apocalyptic number.

It is an amenable number.

21574221065 is a deficient number, since it is larger than the sum of its proper divisors (5176655095).

21574221065 is a wasteful number, since it uses less digits than its factorization.

21574221065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 138992.

The product of its (nonzero) digits is 33600, while the sum is 35.

Adding to 21574221065 its reverse (56012247512), we get a palindrome (77586468577).

The spelling of 21574221065 in words is "twenty-one billion, five hundred seventy-four million, two hundred twenty-one thousand, sixty-five".