13212812809 has 9 divisors (see below), whose sum is σ = 15370942791. Its totient is φ = 11324578440.

The previous prime is 13212812803. The next prime is 13212812827. The reversal of 13212812809 is 90821821231.

The square root of 13212812809 is 114947.

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

It can be written as a sum of positive squares in only one way, i.e., 130028409 + 13082784400 = 11403^2 + 114380^2 .

It is not a de Polignac number, because 13212812809 - 2⁷ = 13212812681 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13212812803) 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, 796419 + ... + 812839.

Almost surely, 2^13212812809 is an apocalyptic number.

13212812809 is the 114947-th square number.

13212812809 is the 57474-th centered octagonal number.

It is an amenable number.

13212812809 is a deficient number, since it is larger than the sum of its proper divisors (2158129982).

13212812809 is an frugal number, since it uses more digits than its factorization.

13212812809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32856 (or 16428 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 37.

The spelling of 13212812809 in words is "thirteen billion, two hundred twelve million, eight hundred twelve thousand, eight hundred nine".