82121878494 has 24 divisors (see below), whose sum is σ = 178341679152. Its totient is φ = 27310737600.

The previous prime is 82121878469. The next prime is 82121878507. The reversal of 82121878494 is 49487812128.

82121878494 is a `hidden beast` number, since 82 + 1 + 2 + 1 + 8 + 78 + 494 = 666.

It is a super-3 number, since 3×82121878494³ (a number of 34 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 82121878494.

It is a congruent number.

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, 5260482 + ... + 5276069.

It is an arithmetic number, because the mean of its divisors is an integer number (7430903298).

Almost surely, 2^82121878494 is an apocalyptic number.

82121878494 is an abundant number, since it is smaller than the sum of its proper divisors (96219800658).

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

82121878494 is a wasteful number, since it uses less digits than its factorization.

82121878494 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10536992 (or 10536989 counting only the distinct ones).

The product of its digits is 2064384, while the sum is 54.

The spelling of 82121878494 in words is "eighty-two billion, one hundred twenty-one million, eight hundred seventy-eight thousand, four hundred ninety-four".