19689909 has 24 divisors (see below), whose sum is σ = 28932960. Its totient is φ = 11876832.

The previous prime is 19689907. The next prime is 19689913. The reversal of 19689909 is 90998691.

It is not a de Polignac number, because 19689909 - 2¹ = 19689907 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19689907) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 29827 + ... + 30479.

It is an arithmetic number, because the mean of its divisors is an integer number (1205540).

Almost surely, 2^19689909 is an apocalyptic number.

19689909 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

19689909 is a deficient number, since it is larger than the sum of its proper divisors (9243051).

19689909 is a wasteful number, since it uses less digits than its factorization.

19689909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 721 (or 698 counting only the distinct ones).

The product of its (nonzero) digits is 314928, while the sum is 51.

The square root of 19689909 is about 4437.3312925676. The cubic root of 19689909 is about 270.0315875253.

The spelling of 19689909 in words is "nineteen million, six hundred eighty-nine thousand, nine hundred nine".