2170021 has 8 divisors (see below), whose sum is σ = 2497664. Its totient is φ = 1846800.

The previous prime is 2169997. The next prime is 2170039. The reversal of 2170021 is 1200712.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 2170021 - 2⁹ = 2169509 is a prime.

It is a super-2 number, since 2×2170021² = 9417982280882, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2169983 and 2170010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2170061) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 31 + ... + 2083.

It is an arithmetic number, because the mean of its divisors is an integer number (312208).

2^2170021 is an apocalyptic number.

It is an amenable number.

2170021 is a deficient number, since it is larger than the sum of its proper divisors (327643).

2170021 is a wasteful number, since it uses less digits than its factorization.

2170021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2211.

The product of its (nonzero) digits is 28, while the sum is 13.

The square root of 2170021 is about 1473.0991141128. The cubic root of 2170021 is about 129.4656766666.

Adding to 2170021 its reverse (1200712), we get a palindrome (3370733).

The spelling of 2170021 in words is "two million, one hundred seventy thousand, twenty-one".