19804513 has 2 divisors, whose sum is σ = 19804514. Its totient is φ = 19804512.

The previous prime is 19804489. The next prime is 19804529. The reversal of 19804513 is 31540891.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11778624 + 8025889 = 3432^2 + 2833^2 .

It is a cyclic number.

It is not a de Polignac number, because 19804513 - 2⁵ = 19804481 is a prime.

It is not a weakly prime, because it can be changed into another prime (19804573) by changing a digit.

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

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9902256 + 9902257.

It is an arithmetic number, because the mean of its divisors is an integer number (9902257).

Almost surely, 2^19804513 is an apocalyptic number.

It is an amenable number.

19804513 is a deficient number, since it is larger than the sum of its proper divisors (1).

19804513 is an equidigital number, since it uses as much as digits as its factorization.

19804513 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4320, while the sum is 31.

The square root of 19804513 is about 4450.2261740276. The cubic root of 19804513 is about 270.5544755400.

The spelling of 19804513 in words is "nineteen million, eight hundred four thousand, five hundred thirteen".