19864850 has 12 divisors (see below), whose sum is σ = 36948714. Its totient is φ = 7945920.

The previous prime is 19864837. The next prime is 19864903. The reversal of 19864850 is 5846891.

It is a Cunningham number, because it is equal to 4457²+1.

It can be written as a sum of positive squares in 3 ways, for example, as 18309841 + 1555009 = 4279^2 + 1247^2 .

It is a super-2 number, since 2×19864850² = 789224531045000, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 19864798 and 19864807.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 198599 + ... + 198698.

Almost surely, 2^19864850 is an apocalyptic number.

19864850 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

19864850 is a deficient number, since it is larger than the sum of its proper divisors (17083864).

19864850 is a wasteful number, since it uses less digits than its factorization.

19864850 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 397309 (or 397304 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 41.

The square root of 19864850 is about 4457.0001121831. Note that the first 3 decimals coincide. The cubic root of 19864850 is about 270.8289566683.

The spelling of 19864850 in words is "nineteen million, eight hundred sixty-four thousand, eight hundred fifty".