72193909 has 2 divisors, whose sum is σ = 72193910. Its totient is φ = 72193908.

The previous prime is 72193879. The next prime is 72193921. The reversal of 72193909 is 90939127.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 46539684 + 25654225 = 6822^2 + 5065^2 .

It is an emirp because it is prime and its reverse (90939127) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 72193909 - 2⁹ = 72193397 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72193949) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36096954 + 36096955.

It is an arithmetic number, because the mean of its divisors is an integer number (36096955).

Almost surely, 2^72193909 is an apocalyptic number.

It is an amenable number.

72193909 is a deficient number, since it is larger than the sum of its proper divisors (1).

72193909 is an equidigital number, since it uses as much as digits as its factorization.

72193909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 30618, while the sum is 40.

The square root of 72193909 is about 8496.6998887803. The cubic root of 72193909 is about 416.3898992580.

The spelling of 72193909 in words is "seventy-two million, one hundred ninety-three thousand, nine hundred nine".