19808057 has 2 divisors, whose sum is σ = 19808058. Its totient is φ = 19808056.

The previous prime is 19808053. The next prime is 19808071. The reversal of 19808057 is 75080891.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13512976 + 6295081 = 3676^2 + 2509^2 .

It is a cyclic number.

It is not a de Polignac number, because 19808057 - 2² = 19808053 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 19808057.

It is not a weakly prime, because it can be changed into another prime (19808053) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9904028 + 9904029.

It is an arithmetic number, because the mean of its divisors is an integer number (9904029).

Almost surely, 2^19808057 is an apocalyptic number.

It is an amenable number.

19808057 is a deficient number, since it is larger than the sum of its proper divisors (1).

19808057 is an equidigital number, since it uses as much as digits as its factorization.

19808057 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 20160, while the sum is 38.

The square root of 19808057 is about 4450.6243382249. The cubic root of 19808057 is about 270.5706130718.

The spelling of 19808057 in words is "nineteen million, eight hundred eight thousand, fifty-seven".