72706409 has 2 divisors, whose sum is σ = 72706410. Its totient is φ = 72706408.

The previous prime is 72706397. The next prime is 72706453. The reversal of 72706409 is 90460727.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 45697600 + 27008809 = 6760^2 + 5197^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-72706409 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (72706499) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36353204 + 36353205.

It is an arithmetic number, because the mean of its divisors is an integer number (36353205).

Almost surely, 2^72706409 is an apocalyptic number.

It is an amenable number.

72706409 is a deficient number, since it is larger than the sum of its proper divisors (1).

72706409 is an equidigital number, since it uses as much as digits as its factorization.

72706409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 21168, while the sum is 35.

The square root of 72706409 is about 8526.8053220418. The cubic root of 72706409 is about 417.3728853938.

The spelling of 72706409 in words is "seventy-two million, seven hundred six thousand, four hundred nine".