19999857 has 8 divisors (see below), whose sum is σ = 27825984. Its totient is φ = 12753488.

The previous prime is 19999843. The next prime is 19999873. The reversal of 19999857 is 75899991.

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 19999857 - 2⁷ = 19999729 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 19999797 and 19999806.

It is not an unprimeable number, because it can be changed into a prime (19999817) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 144858 + ... + 144995.

It is an arithmetic number, because the mean of its divisors is an integer number (3478248).

Almost surely, 2^19999857 is an apocalyptic number.

It is an amenable number.

19999857 is a deficient number, since it is larger than the sum of its proper divisors (7826127).

19999857 is a wasteful number, since it uses less digits than its factorization.

19999857 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 289879.

The product of its digits is 1837080, while the sum is 57.

The square root of 19999857 is about 4472.1199670850. The cubic root of 19999857 is about 271.4411147218.

The spelling of 19999857 in words is "nineteen million, nine hundred ninety-nine thousand, eight hundred fifty-seven".