82180661 has 4 divisors (see below), whose sum is σ = 82223232. Its totient is φ = 82138092.

The previous prime is 82180649. The next prime is 82180667. The reversal of 82180661 is 16608128.

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 82180661 - 2²² = 77986357 is a prime.

It is a super-2 number, since 2×82180661² = 13507322084793842, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (82180667) 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, 18245 + ... + 22298.

It is an arithmetic number, because the mean of its divisors is an integer number (20555808).

Almost surely, 2^82180661 is an apocalyptic number.

It is an amenable number.

82180661 is a deficient number, since it is larger than the sum of its proper divisors (42571).

82180661 is a wasteful number, since it uses less digits than its factorization.

82180661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42570.

The product of its (nonzero) digits is 4608, while the sum is 32.

The square root of 82180661 is about 9065.3549847758. The cubic root of 82180661 is about 434.7669707980.

Adding to 82180661 its reverse (16608128), we get a palindrome (98788789).

The spelling of 82180661 in words is "eighty-two million, one hundred eighty thousand, six hundred sixty-one".