82172320040 has 32 divisors (see below), whose sum is σ = 186793787880. Its totient is φ = 32530071552.

The previous prime is 82172320039. The next prime is 82172320067. The reversal of 82172320040 is 4002327128.

It can be written as a sum of positive squares in 4 ways, for example, as 41950413124 + 40221906916 = 204818^2 + 200554^2 .

It is a junction number, because it is equal to n+sod(n) for n = 82172319985 and 82172320012.

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, 10585337 + ... + 10593096.

Almost surely, 2^82172320040 is an apocalyptic number.

It is an amenable number.

82172320040 is an abundant number, since it is smaller than the sum of its proper divisors (104621467840).

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

82172320040 is a wasteful number, since it uses less digits than its factorization.

82172320040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21178541 (or 21178537 counting only the distinct ones).

The product of its (nonzero) digits is 5376, while the sum is 29.

Adding to 82172320040 its reverse (4002327128), we get a palindrome (86174647168).

The spelling of 82172320040 in words is "eighty-two billion, one hundred seventy-two million, three hundred twenty thousand, forty".