19804139 has 8 divisors (see below), whose sum is σ = 20725200. Its totient is φ = 18903456.

The previous prime is 19804111. The next prime is 19804153. The reversal of 19804139 is 93140891.

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

It is a cyclic number.

It is not a de Polignac number, because 19804139 - 2¹⁶ = 19738603 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 19804099 and 19804108.

It is not an unprimeable number, because it can be changed into a prime (19804159) 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, 3089 + ... + 7010.

It is an arithmetic number, because the mean of its divisors is an integer number (2590650).

Almost surely, 2^19804139 is an apocalyptic number.

19804139 is a deficient number, since it is larger than the sum of its proper divisors (921061).

19804139 is a wasteful number, since it uses less digits than its factorization.

19804139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10189.

The product of its (nonzero) digits is 7776, while the sum is 35.

The square root of 19804139 is about 4450.1841534930. The cubic root of 19804139 is about 270.5527724263.

The spelling of 19804139 in words is "nineteen million, eight hundred four thousand, one hundred thirty-nine".