82691780 has 12 divisors (see below), whose sum is σ = 173652780. Its totient is φ = 33076704.

The previous prime is 82691779. The next prime is 82691801. The reversal of 82691780 is 8719628.

It can be written as a sum of positive squares in 2 ways, for example, as 62188996 + 20502784 = 7886^2 + 4528^2 .

It is a hoax number, since the sum of its digits (41) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2067275 + ... + 2067314.

It is an arithmetic number, because the mean of its divisors is an integer number (14471065).

Almost surely, 2^82691780 is an apocalyptic number.

It is an amenable number.

82691780 is an abundant number, since it is smaller than the sum of its proper divisors (90961000).

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

82691780 is a wasteful number, since it uses less digits than its factorization.

82691780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4134598 (or 4134596 counting only the distinct ones).

The product of its (nonzero) digits is 48384, while the sum is 41.

The square root of 82691780 is about 9093.5020756582. The cubic root of 82691780 is about 435.6664466232. Note that the first 3 decimals are identical.

The spelling of 82691780 in words is "eighty-two million, six hundred ninety-one thousand, seven hundred eighty".