19399999 has 2 divisors, whose sum is σ = 19400000. Its totient is φ = 19399998.

The previous prime is 19399993. The next prime is 19400023. The reversal of 19399999 is 99999391.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 19399999 - 2²¹ = 17302847 is a prime.

It is a super-2 number, since 2×19399999² = 752719922400002, which contains 22 as substring.

19399999 is a modest number, since divided by 9999 gives 1939 as remainder.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19399993) 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, 9699999 + 9700000.

It is an arithmetic number, because the mean of its divisors is an integer number (9700000).

Almost surely, 2^19399999 is an apocalyptic number.

19399999 is a deficient number, since it is larger than the sum of its proper divisors (1).

19399999 is an equidigital number, since it uses as much as digits as its factorization.

19399999 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1594323, while the sum is 58.

The square root of 19399999 is about 4404.5429955899. The cubic root of 19399999 is about 268.6997335951.

The spelling of 19399999 in words is "nineteen million, three hundred ninety-nine thousand, nine hundred ninety-nine".