82180621 has 2 divisors, whose sum is σ = 82180622. Its totient is φ = 82180620.

The previous prime is 82180607. The next prime is 82180639. The reversal of 82180621 is 12608128.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 75446596 + 6734025 = 8686^2 + 2595^2 .

It is a cyclic number.

It is not a de Polignac number, because 82180621 - 2¹¹ = 82178573 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 82180621.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (82180421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41090310 + 41090311.

It is an arithmetic number, because the mean of its divisors is an integer number (41090311).

Almost surely, 2^82180621 is an apocalyptic number.

It is an amenable number.

82180621 is a deficient number, since it is larger than the sum of its proper divisors (1).

82180621 is an equidigital number, since it uses as much as digits as its factorization.

82180621 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1536, while the sum is 28.

The square root of 82180621 is about 9065.3527785740. The cubic root of 82180621 is about 434.7669002596.

Adding to 82180621 its reverse (12608128), we get a palindrome (94788749).

The spelling of 82180621 in words is "eighty-two million, one hundred eighty thousand, six hundred twenty-one".