82161620 has 24 divisors (see below), whose sum is σ = 172710888. Its totient is φ = 32832000.

The previous prime is 82161613. The next prime is 82161641. The reversal of 82161620 is 2616128.

It can be written as a sum of positive squares in 4 ways, for example, as 2202256 + 79959364 = 1484^2 + 8942^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 82161620.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 34880 + ... + 37160.

It is an arithmetic number, because the mean of its divisors is an integer number (7196287).

Almost surely, 2^82161620 is an apocalyptic number.

It is an amenable number.

82161620 is an abundant number, since it is smaller than the sum of its proper divisors (90549268).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

82161620 is a wasteful number, since it uses less digits than its factorization.

82161620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4091 (or 4089 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 26.

The square root of 82161620 is about 9064.3047168550. The cubic root of 82161620 is about 434.7333901590.

Adding to 82161620 its reverse (2616128), we get a palindrome (84777748).

The spelling of 82161620 in words is "eighty-two million, one hundred sixty-one thousand, six hundred twenty".