19840745 has 4 divisors (see below), whose sum is σ = 23808900. Its totient is φ = 15872592.

The previous prime is 19840703. The next prime is 19840747. The reversal of 19840745 is 54704891.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 54704891 = 3511 ⋅15581.

It can be written as a sum of positive squares in 2 ways, for example, as 12201049 + 7639696 = 3493^2 + 2764^2 .

It is a cyclic number.

It is not a de Polignac number, because 19840745 - 2¹⁶ = 19775209 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 19840699 and 19840708.

It is not an unprimeable number, because it can be changed into a prime (19840747) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1984070 + ... + 1984079.

It is an arithmetic number, because the mean of its divisors is an integer number (5952225).

Almost surely, 2^19840745 is an apocalyptic number.

It is an amenable number.

19840745 is a deficient number, since it is larger than the sum of its proper divisors (3968155).

19840745 is an equidigital number, since it uses as much as digits as its factorization.

19840745 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3968154.

The product of its (nonzero) digits is 40320, while the sum is 38.

The square root of 19840745 is about 4454.2951181977. The cubic root of 19840745 is about 270.7193665399.

The spelling of 19840745 in words is "nineteen million, eight hundred forty thousand, seven hundred forty-five".