19978801 has 2 divisors, whose sum is σ = 19978802. Its totient is φ = 19978800.

The previous prime is 19978771. The next prime is 19978817. The reversal of 19978801 is 10887991.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11122225 + 8856576 = 3335^2 + 2976^2 .

It is a cyclic number.

It is not a de Polignac number, because 19978801 - 2⁵ = 19978769 is a prime.

It is not a weakly prime, because it can be changed into another prime (19978831) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9989400 + 9989401.

It is an arithmetic number, because the mean of its divisors is an integer number (9989401).

Almost surely, 2^19978801 is an apocalyptic number.

It is an amenable number.

19978801 is a deficient number, since it is larger than the sum of its proper divisors (1).

19978801 is an equidigital number, since it uses as much as digits as its factorization.

19978801 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 36288, while the sum is 43.

The square root of 19978801 is about 4469.7652063615. The cubic root of 19978801 is about 271.3458228563.

The spelling of 19978801 in words is "nineteen million, nine hundred seventy-eight thousand, eight hundred one".