19798081 has 4 divisors (see below), whose sum is σ = 20962692. Its totient is φ = 18633472.

The previous prime is 19798069. The next prime is 19798087. The reversal of 19798081 is 18089791.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 13249600 + 6548481 = 3640^2 + 2559^2 .

It is a cyclic number.

It is not a de Polignac number, because 19798081 - 2⁵ = 19798049 is a prime.

It is a super-3 number, since 3×19798081³ (a number of 23 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19798087) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 582280 + ... + 582313.

It is an arithmetic number, because the mean of its divisors is an integer number (5240673).

Almost surely, 2^19798081 is an apocalyptic number.

It is an amenable number.

19798081 is a deficient number, since it is larger than the sum of its proper divisors (1164611).

19798081 is a wasteful number, since it uses less digits than its factorization.

19798081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1164610.

The product of its (nonzero) digits is 36288, while the sum is 43.

The square root of 19798081 is about 4449.5034554431. The cubic root of 19798081 is about 270.5251826408.

The spelling of 19798081 in words is "nineteen million, seven hundred ninety-eight thousand, eighty-one".