19228681 has 4 divisors (see below), whose sum is σ = 19249812. Its totient is φ = 19207552.

The previous prime is 19228673. The next prime is 19228721. The reversal of 19228681 is 18682291.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 18682291 = 59 ⋅316649.

It can be written as a sum of positive squares in 2 ways, for example, as 10725625 + 8503056 = 3275^2 + 2916^2 .

It is a cyclic number.

It is not a de Polignac number, because 19228681 - 2³ = 19228673 is a prime.

It is a super-2 number, since 2×19228681² = 739484345999522, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 19228681.

It is not an unprimeable number, because it can be changed into a prime (19228661) 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, 9136 + ... + 11041.

It is an arithmetic number, because the mean of its divisors is an integer number (4812453).

Almost surely, 2^19228681 is an apocalyptic number.

It is an amenable number.

19228681 is a deficient number, since it is larger than the sum of its proper divisors (21131).

19228681 is an equidigital number, since it uses as much as digits as its factorization.

19228681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21130.

The product of its digits is 13824, while the sum is 37.

The square root of 19228681 is about 4385.0519951307. The cubic root of 19228681 is about 267.9064470747.

The spelling of 19228681 in words is "nineteen million, two hundred twenty-eight thousand, six hundred eighty-one".