72470809 has 2 divisors, whose sum is σ = 72470810. Its totient is φ = 72470808.

The previous prime is 72470803. The next prime is 72470843. The reversal of 72470809 is 90807427.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 69355584 + 3115225 = 8328^2 + 1765^2 .

It is a cyclic number.

It is not a de Polignac number, because 72470809 - 2¹¹ = 72468761 is a prime.

It is a super-2 number, since 2×72470809² = 10504036314228962, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (72470803) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36235404 + 36235405.

It is an arithmetic number, because the mean of its divisors is an integer number (36235405).

Almost surely, 2^72470809 is an apocalyptic number.

It is an amenable number.

72470809 is a deficient number, since it is larger than the sum of its proper divisors (1).

72470809 is an equidigital number, since it uses as much as digits as its factorization.

72470809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 28224, while the sum is 37.

The square root of 72470809 is about 8512.9788558412. The cubic root of 72470809 is about 416.9215750781.

The spelling of 72470809 in words is "seventy-two million, four hundred seventy thousand, eight hundred nine".