19840939 has 4 divisors (see below), whose sum is σ = 19884256. Its totient is φ = 19797624.

The previous prime is 19840937. The next prime is 19840967. The reversal of 19840939 is 93904891.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 19840939 - 2¹ = 19840937 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 19840895 and 19840904.

It is not an unprimeable number, because it can be changed into a prime (19840937) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20964 + ... + 21889.

It is an arithmetic number, because the mean of its divisors is an integer number (4971064).

Almost surely, 2^19840939 is an apocalyptic number.

19840939 is a deficient number, since it is larger than the sum of its proper divisors (43317).

19840939 is an equidigital number, since it uses as much as digits as its factorization.

19840939 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43316.

The product of its (nonzero) digits is 69984, while the sum is 43.

The square root of 19840939 is about 4454.3168948785. The cubic root of 19840939 is about 270.7202488889.

The spelling of 19840939 in words is "nineteen million, eight hundred forty thousand, nine hundred thirty-nine".