19792009 has 2 divisors, whose sum is σ = 19792010. Its totient is φ = 19792008.

The previous prime is 19791973. The next prime is 19792013. The reversal of 19792009 is 90029791.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17977600 + 1814409 = 4240^2 + 1347^2 .

It is an emirp because it is prime and its reverse (90029791) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 19792009 - 2¹⁷ = 19660937 is a prime.

It is not a weakly prime, because it can be changed into another prime (19792039) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9896004 + 9896005.

It is an arithmetic number, because the mean of its divisors is an integer number (9896005).

Almost surely, 2^19792009 is an apocalyptic number.

It is an amenable number.

19792009 is a deficient number, since it is larger than the sum of its proper divisors (1).

19792009 is an equidigital number, since it uses as much as digits as its factorization.

19792009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10206, while the sum is 37.

The square root of 19792009 is about 4448.8210797918. The cubic root of 19792009 is about 270.4975234471.

The spelling of 19792009 in words is "nineteen million, seven hundred ninety-two thousand, nine".