21896344498609 has 135 divisors (see below), whose sum is σ = 27498695564067. Its totient is φ = 17433247797504.

The previous prime is 21896344498597. The next prime is 21896344498619. The reversal of 21896344498609 is 90689444369812.

The square root of 21896344498609 is 4679353.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 13 ways, for example, as 7761210951025 + 14135133547584 = 2785895^2 + 3759672^2 .

It is not a de Polignac number, because 21896344498609 - 2¹⁵ = 21896344465841 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21896344498619) by changing a digit.

It is a polite number, since it can be written in 134 ways as a sum of consecutive naturals, for example, 246026342637 + ... + 246026342725.

Almost surely, 2^{21896344498609} is an apocalyptic number.

21896344498609 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

21896344498609 is the 4679353-rd square number.

21896344498609 is the 2339677-th centered octagonal number.

It is an amenable number.

21896344498609 is a deficient number, since it is larger than the sum of its proper divisors (5602351065458).

21896344498609 is an frugal number, since it uses more digits than its factorization.

21896344498609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 338 (or 162 counting only the distinct ones).

The product of its (nonzero) digits is 644972544, while the sum is 73.

The spelling of 21896344498609 in words is "twenty-one trillion, eight hundred ninety-six billion, three hundred forty-four million, four hundred ninety-eight thousand, six hundred nine".