19995381 has 18 divisors (see below), whose sum is σ = 33598422. Its totient is φ = 11425680.

The previous prime is 19995359. The next prime is 19995389. The reversal of 19995381 is 18359991.

It can be written as a sum of positive squares in only one way, i.e., 10595025 + 9400356 = 3255^2 + 3066^2 .

It is not a de Polignac number, because 19995381 - 2⁷ = 19995253 is a prime.

It is a super-3 number, since 3×19995381³ (a number of 23 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19995389) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 22230 + ... + 23111.

It is an arithmetic number, because the mean of its divisors is an integer number (1866579).

Almost surely, 2^19995381 is an apocalyptic number.

It is an amenable number.

19995381 is a deficient number, since it is larger than the sum of its proper divisors (13603041).

19995381 is a wasteful number, since it uses less digits than its factorization.

19995381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45361 (or 45351 counting only the distinct ones).

The product of its digits is 87480, while the sum is 45.

The square root of 19995381 is about 4471.6195052799. The cubic root of 19995381 is about 271.4208635590.

The spelling of 19995381 in words is "nineteen million, nine hundred ninety-five thousand, three hundred eighty-one".