82197540 has 36 divisors (see below), whose sum is σ = 249333084. Its totient is φ = 21919296.

The previous prime is 82197539. The next prime is 82197551. The reversal of 82197540 is 4579128.

82197540 is a `hidden beast` number, since 8 + 21 + 97 + 540 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 28965924 + 53231616 = 5382^2 + 7296^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 82197495 and 82197504.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 228147 + ... + 228506.

It is an arithmetic number, because the mean of its divisors is an integer number (6925919).

Almost surely, 2^82197540 is an apocalyptic number.

It is an amenable number.

82197540 is an abundant number, since it is smaller than the sum of its proper divisors (167135544).

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

82197540 is a wasteful number, since it uses less digits than its factorization.

82197540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 456668 (or 456663 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 36.

The square root of 82197540 is about 9066.2858988673. The cubic root of 82197540 is about 434.7967342048.

The spelling of 82197540 in words is "eighty-two million, one hundred ninety-seven thousand, five hundred forty".