19989841 has 9 divisors (see below), whose sum is σ = 21315931. Its totient is φ = 18742432.

The previous prime is 19989839. The next prime is 19989859. The reversal of 19989841 is 14898991.

The square root of 19989841 is 4471.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 15563025 + 4426816 = 3945^2 + 2104^2 .

It is not a de Polignac number, because 19989841 - 2¹ = 19989839 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19989811) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 75876 + ... + 76138.

Almost surely, 2^19989841 is an apocalyptic number.

19989841 is the 4471-st square number.

19989841 is the 2236-th centered octagonal number.

It is an amenable number.

19989841 is a deficient number, since it is larger than the sum of its proper divisors (1326090).

19989841 is an frugal number, since it uses more digits than its factorization.

19989841 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 560 (or 280 counting only the distinct ones).

The product of its digits is 186624, while the sum is 49.

The cubic root of 19989841 is about 271.3957942613.

Multiplying 19989841 by its sum of digits (49), we get a square (979502209 = 31297²).

Multiplying 19989841 by its product of digits (186624), we get a square (3730584086784 = 1931472²).

The spelling of 19989841 in words is "nineteen million, nine hundred eighty-nine thousand, eight hundred forty-one".