7170021 has 18 divisors (see below), whose sum is σ = 10714470. Its totient is φ = 4620240.

The previous prime is 7170019. The next prime is 7170041. The reversal of 7170021 is 1200717.

It can be written as a sum of positive squares in only one way, i.e., 6305121 + 864900 = 2511^2 + 930^2 .

It is not a de Polignac number, because 7170021 - 2¹ = 7170019 is a prime.

It is a super-2 number, since 2×7170021² = 102818402280882, which contains 22 as substring.

It is a Curzon number.

7170021 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 7169976 and 7170003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7170041) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 8235 + ... + 9063.

Almost surely, 2^7170021 is an apocalyptic number.

It is an amenable number.

7170021 is a deficient number, since it is larger than the sum of its proper divisors (3544449).

7170021 is a wasteful number, since it uses less digits than its factorization.

7170021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 897 (or 863 counting only the distinct ones).

The product of its (nonzero) digits is 98, while the sum is 18.

The square root of 7170021 is about 2677.6894890932. The cubic root of 7170021 is about 192.8295003297.

Adding to 7170021 its reverse (1200717), we get a palindrome (8370738).

It can be divided in two parts, 717002 and 1, that added together give a triangular number (717003 = T₁₁₉₇).

The spelling of 7170021 in words is "seven million, one hundred seventy thousand, twenty-one".