65220209265409 has 45 divisors (see below), whose sum is σ = 74165136450195. Its totient is φ = 57351832744800.

The previous prime is 65220209265403. The next prime is 65220209265433. The reversal of 65220209265409 is 90456290202256.

The square root of 65220209265409 is 8075903.

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., 4815106092225 + 60405103173184 = 2194335^2 + 7772072^2 .

It is not a de Polignac number, because 65220209265409 - 2¹⁷ = 65220209134337 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (65220209265403) by changing a digit.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 30292711077 + ... + 30292713229.

Almost surely, 2^{65220209265409} is an apocalyptic number.

65220209265409 is the 8075903-rd square number.

65220209265409 is the 4037952-nd centered octagonal number.

It is an amenable number.

65220209265409 is a deficient number, since it is larger than the sum of its proper divisors (8944927184786).

65220209265409 is an frugal number, since it uses more digits than its factorization.

65220209265409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4412 (or 2195 counting only the distinct ones).

The product of its (nonzero) digits is 4665600, while the sum is 52.

The spelling of 65220209265409 in words is "sixty-five trillion, two hundred twenty billion, two hundred nine million, two hundred sixty-five thousand, four hundred nine".