19431409 has 2 divisors, whose sum is σ = 19431410. Its totient is φ = 19431408.

The previous prime is 19431329. The next prime is 19431413. The reversal of 19431409 is 90413491.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19184400 + 247009 = 4380^2 + 497^2 .

It is a cyclic number.

It is not a de Polignac number, because 19431409 - 2⁹ = 19430897 is a prime.

It is a Chen prime.

It is equal to p_1236766 and since 19431409 and 1236766 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (19431449) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9715704 + 9715705.

It is an arithmetic number, because the mean of its divisors is an integer number (9715705).

Almost surely, 2^19431409 is an apocalyptic number.

It is an amenable number.

19431409 is a deficient number, since it is larger than the sum of its proper divisors (1).

19431409 is an equidigital number, since it uses as much as digits as its factorization.

19431409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3888, while the sum is 31.

The square root of 19431409 is about 4408.1071901668. The cubic root of 19431409 is about 268.8446701629.

The spelling of 19431409 in words is "nineteen million, four hundred thirty-one thousand, four hundred nine".