72209779 has 2 divisors, whose sum is σ = 72209780. Its totient is φ = 72209778.

The previous prime is 72209773. The next prime is 72209789. The reversal of 72209779 is 97790227.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-72209779 is a prime.

It is not a weakly prime, because it can be changed into another prime (72209773) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36104889 + 36104890.

It is an arithmetic number, because the mean of its divisors is an integer number (36104890).

Almost surely, 2^72209779 is an apocalyptic number.

72209779 is a deficient number, since it is larger than the sum of its proper divisors (1).

72209779 is an equidigital number, since it uses as much as digits as its factorization.

72209779 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 111132, while the sum is 43.

The square root of 72209779 is about 8497.6337294567. The cubic root of 72209779 is about 416.4204079424.

The spelling of 72209779 in words is "seventy-two million, two hundred nine thousand, seven hundred seventy-nine".