19713409 has 2 divisors, whose sum is σ = 19713410. Its totient is φ = 19713408.

The previous prime is 19713389. The next prime is 19713433. The reversal of 19713409 is 90431791.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17472400 + 2241009 = 4180^2 + 1497^2 .

It is a cyclic number.

It is not a de Polignac number, because 19713409 - 2⁵ = 19713377 is a prime.

It is not a weakly prime, because it can be changed into another prime (19713809) 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, 9856704 + 9856705.

It is an arithmetic number, because the mean of its divisors is an integer number (9856705).

Almost surely, 2^19713409 is an apocalyptic number.

It is an amenable number.

19713409 is a deficient number, since it is larger than the sum of its proper divisors (1).

19713409 is an equidigital number, since it uses as much as digits as its factorization.

19713409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6804, while the sum is 34.

The square root of 19713409 is about 4439.9784909389. The cubic root of 19713409 is about 270.1389728095.

The spelling of 19713409 in words is "nineteen million, seven hundred thirteen thousand, four hundred nine".