19906789 has 12 divisors (see below), whose sum is σ = 23957100. Its totient is φ = 16473408.

The previous prime is 19906781. The next prime is 19906793. The reversal of 19906789 is 98760991.

It can be written as a sum of positive squares in 2 ways, for example, as 13198689 + 6708100 = 3633^2 + 2590^2 .

It is not a de Polignac number, because 19906789 - 2³ = 19906781 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (49).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19906781) 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 11 ways as a sum of consecutive naturals, for example, 5584 + ... + 8425.

It is an arithmetic number, because the mean of its divisors is an integer number (1996425).

Almost surely, 2^19906789 is an apocalyptic number.

It is an amenable number.

19906789 is a deficient number, since it is larger than the sum of its proper divisors (4050311).

19906789 is a wasteful number, since it uses less digits than its factorization.

19906789 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14052 (or 14045 counting only the distinct ones).

The product of its (nonzero) digits is 244944, while the sum is 49.

The square root of 19906789 is about 4461.7024777544. The cubic root of 19906789 is about 271.0194155559.

The spelling of 19906789 in words is "nineteen million, nine hundred six thousand, seven hundred eighty-nine".