19940281 has 4 divisors (see below), whose sum is σ = 19984372. Its totient is φ = 19896192.

The previous prime is 19940273. The next prime is 19940293. The reversal of 19940281 is 18204991.

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 17935225 + 2005056 = 4235^2 + 1416^2 .

It is a cyclic number.

It is not a de Polignac number, because 19940281 - 2³ = 19940273 is a prime.

It is a super-2 number, since 2×19940281² = 795229612717922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19940981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21360 + ... + 22273.

It is an arithmetic number, because the mean of its divisors is an integer number (4996093).

Almost surely, 2^19940281 is an apocalyptic number.

It is an amenable number.

19940281 is a deficient number, since it is larger than the sum of its proper divisors (44091).

19940281 is an equidigital number, since it uses as much as digits as its factorization.

19940281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44090.

The product of its (nonzero) digits is 5184, while the sum is 34.

The square root of 19940281 is about 4465.4541762289. The cubic root of 19940281 is about 271.1713217979.

The spelling of 19940281 in words is "nineteen million, nine hundred forty thousand, two hundred eighty-one".