19989845 has 16 divisors (see below), whose sum is σ = 25110000. Its totient is φ = 15257088.

The previous prime is 19989839. The next prime is 19989859. The reversal of 19989845 is 54898991.

It can be written as a sum of positive squares in 8 ways, for example, as 1825201 + 18164644 = 1351^2 + 4262^2 .

It is a cyclic number.

It is not a de Polignac number, because 19989845 - 2¹⁴ = 19973461 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12131 + ... + 13679.

It is an arithmetic number, because the mean of its divisors is an integer number (1569375).

Almost surely, 2^19989845 is an apocalyptic number.

It is an amenable number.

19989845 is a deficient number, since it is larger than the sum of its proper divisors (5120155).

19989845 is a wasteful number, since it uses less digits than its factorization.

19989845 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1672.

The product of its digits is 933120, while the sum is 53.

The square root of 19989845 is about 4471.0004473272. Note that the first 3 decimals coincide. The cubic root of 19989845 is about 271.3958123635.

The spelling of 19989845 in words is "nineteen million, nine hundred eighty-nine thousand, eight hundred forty-five".