43021 has 4 divisors (see below), whose sum is σ = 46944. Its totient is φ = 39100.

The previous prime is 43019. The next prime is 43037. The reversal of 43021 is 12034.

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.

It is a cyclic number.

It is not a de Polignac number, because 43021 - 2¹ = 43019 is a prime.

It is a Duffinian number.

43021 is a lucky number.

It is a nialpdrome in base 15.

It is a junction number, because it is equal to n+sod(n) for n = 42989 and 43007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (43051) 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, 1945 + ... + 1966.

It is an arithmetic number, because the mean of its divisors is an integer number (11736).

2⁴³⁰²¹ is an apocalyptic number.

It is an amenable number.

43021 is a deficient number, since it is larger than the sum of its proper divisors (3923).

43021 is a wasteful number, since it uses less digits than its factorization.

43021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3922.

The product of its (nonzero) digits is 24, while the sum is 10.

The square root of 43021 is about 207.4150428489. The cubic root of 43021 is about 35.0396828818.

Adding to 43021 its reverse (12034), we get a palindrome (55055).

It can be divided in two parts, 4 and 3021, that added together give a square (3025 = 55²).

The spelling of 43021 in words is "forty-three thousand, twenty-one", and thus it is an iban number.