19909745 has 8 divisors (see below), whose sum is σ = 24160680. Its totient is φ = 15748480.

The previous prime is 19909741. The next prime is 19909753. The reversal of 19909745 is 54790991.

It can be written as a sum of positive squares in 4 ways, for example, as 839056 + 19070689 = 916^2 + 4367^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 19909745 - 2² = 19909741 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 19909696 and 19909705.

It is not an unprimeable number, because it can be changed into a prime (19909741) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21926 + ... + 22815.

It is an arithmetic number, because the mean of its divisors is an integer number (3020085).

Almost surely, 2^19909745 is an apocalyptic number.

It is an amenable number.

19909745 is a deficient number, since it is larger than the sum of its proper divisors (4250935).

19909745 is an equidigital number, since it uses as much as digits as its factorization.

19909745 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44835.

The product of its (nonzero) digits is 102060, while the sum is 44.

The square root of 19909745 is about 4462.0337291419. The cubic root of 19909745 is about 271.0328296352.

The spelling of 19909745 in words is "nineteen million, nine hundred nine thousand, seven hundred forty-five".