2021869 has 4 divisors (see below), whose sum is σ = 2034144. Its totient is φ = 2009596.

The previous prime is 2021863. The next prime is 2021879. The reversal of 2021869 is 9681202.

It is a happy number.

2021869 is nontrivially palindromic in base 4.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 9681202 = 2 ⋅4840601.

It is a cyclic number.

It is not a de Polignac number, because 2021869 - 2⁵ = 2021837 is a prime.

It is a super-2 number, since 2×2021869² = 8175908506322, which contains 22 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 (2021863) 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, 5887 + ... + 6220.

It is an arithmetic number, because the mean of its divisors is an integer number (508536).

2^2021869 is an apocalyptic number.

It is an amenable number.

2021869 is a deficient number, since it is larger than the sum of its proper divisors (12275).

2021869 is a wasteful number, since it uses less digits than its factorization.

2021869 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12274.

The product of its (nonzero) digits is 1728, while the sum is 28.

The square root of 2021869 is about 1421.9244002407. The cubic root of 2021869 is about 126.4496615265.

The spelling of 2021869 in words is "two million, twenty-one thousand, eight hundred sixty-nine".