72069209 has 2 divisors, whose sum is σ = 72069210. Its totient is φ = 72069208.

The previous prime is 72069199. The next prime is 72069211. The reversal of 72069209 is 90296027.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 71995225 + 73984 = 8485^2 + 272^2 .

It is a cyclic number.

It is not a de Polignac number, because 72069209 - 2²⁰ = 71020633 is a prime.

Together with 72069211, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (72069259) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36034604 + 36034605.

It is an arithmetic number, because the mean of its divisors is an integer number (36034605).

Almost surely, 2^72069209 is an apocalyptic number.

It is an amenable number.

72069209 is a deficient number, since it is larger than the sum of its proper divisors (1).

72069209 is an equidigital number, since it uses as much as digits as its factorization.

72069209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 13608, while the sum is 35.

The square root of 72069209 is about 8489.3585741209. The cubic root of 72069209 is about 416.1500187023.

The spelling of 72069209 in words is "seventy-two million, sixty-nine thousand, two hundred nine".