82170621 has 12 divisors (see below), whose sum is σ = 127821148. Its totient is φ = 50566464.

The previous prime is 82170589. The next prime is 82170653. The reversal of 82170621 is 12607128.

It is an interprime number because it is at equal distance from previous prime (82170589) and next prime (82170653).

It can be written as a sum of positive squares in 2 ways, for example, as 28676025 + 53494596 = 5355^2 + 7314^2 .

It is not a de Polignac number, because 82170621 - 2⁵ = 82170589 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (82170661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 351040 + ... + 351273.

Almost surely, 2^82170621 is an apocalyptic number.

It is an amenable number.

82170621 is a deficient number, since it is larger than the sum of its proper divisors (45650527).

82170621 is a wasteful number, since it uses less digits than its factorization.

82170621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 702332 (or 702329 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 27.

The square root of 82170621 is about 9064.8012112787. The cubic root of 82170621 is about 434.7492649367.

Adding to 82170621 its reverse (12607128), we get a palindrome (94777749).

The spelling of 82170621 in words is "eighty-two million, one hundred seventy thousand, six hundred twenty-one".