21326805369 has 9 divisors (see below), whose sum is σ = 30806018373. Its totient is φ = 14217578172.

The previous prime is 21326805347. The next prime is 21326805373. The reversal of 21326805369 is 96350862312.

The square root of 21326805369 is 146037.

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

21326805369 is a `hidden beast` number, since 2 + 1 + 32 + 6 + 80 + 536 + 9 = 666.

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 21326805369 - 2³³ = 12736870777 is a prime.

It is a super-2 number, since 2×21326805369² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21326805169) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 413772 + ... + 462450.

Almost surely, 2^21326805369 is an apocalyptic number.

21326805369 is the 146037-th square number.

21326805369 is the 73019-th centered octagonal number.

It is an amenable number.

21326805369 is a deficient number, since it is larger than the sum of its proper divisors (9479213004).

21326805369 is an frugal number, since it uses more digits than its factorization.

21326805369 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 97364 (or 48682 counting only the distinct ones).

The product of its (nonzero) digits is 466560, while the sum is 45.

The spelling of 21326805369 in words is "twenty-one billion, three hundred twenty-six million, eight hundred five thousand, three hundred sixty-nine".