20228861 has 4 divisors (see below), whose sum is σ = 21418812. Its totient is φ = 19038912.

The previous prime is 20228849. The next prime is 20228869. The reversal of 20228861 is 16882202.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16882202 = 2 ⋅8441101.

It can be written as a sum of positive squares in 2 ways, for example, as 7873636 + 12355225 = 2806^2 + 3515^2 .

It is not a de Polignac number, because 20228861 - 2¹⁴ = 20212477 is a prime.

It is a super-3 number, since 3×20228861³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20228869) 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, 594950 + ... + 594983.

It is an arithmetic number, because the mean of its divisors is an integer number (5354703).

Almost surely, 2^20228861 is an apocalyptic number.

It is an amenable number.

20228861 is a deficient number, since it is larger than the sum of its proper divisors (1189951).

20228861 is a wasteful number, since it uses less digits than its factorization.

20228861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1189950.

The product of its (nonzero) digits is 3072, while the sum is 29.

The square root of 20228861 is about 4497.6506089291. The cubic root of 20228861 is about 272.4732111813.

The spelling of 20228861 in words is "twenty million, two hundred twenty-eight thousand, eight hundred sixty-one".