19808923 has 2 divisors, whose sum is σ = 19808924. Its totient is φ = 19808922.

The previous prime is 19808917. The next prime is 19808947. The reversal of 19808923 is 32980891.

It is a weak prime.

It is an emirp because it is prime and its reverse (32980891) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 19808923 - 2¹³ = 19800731 is a prime.

It is not a weakly prime, because it can be changed into another prime (19808993) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9904461 + 9904462.

It is an arithmetic number, because the mean of its divisors is an integer number (9904462).

Almost surely, 2^19808923 is an apocalyptic number.

19808923 is a deficient number, since it is larger than the sum of its proper divisors (1).

19808923 is an equidigital number, since it uses as much as digits as its factorization.

19808923 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 31104, while the sum is 40.

The square root of 19808923 is about 4450.7216268825. The cubic root of 19808923 is about 270.5745560925.

The spelling of 19808923 in words is "nineteen million, eight hundred eight thousand, nine hundred twenty-three".