81658228776528 has 20 divisors (see below), whose sum is σ = 210950424339488. Its totient is φ = 27219409592160.

The previous prime is 81658228776511. The next prime is 81658228776529. The reversal of 81658228776528 is 82567782285618.

It is a self number, because there is not a number n which added to its sum of digits gives 81658228776528.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81658228776529) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 850606549708 + ... + 850606549803.

Almost surely, 2^{81658228776528} is an apocalyptic number.

It is an amenable number.

81658228776528 is an abundant number, since it is smaller than the sum of its proper divisors (129292195562960).

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

81658228776528 is a wasteful number, since it uses less digits than its factorization.

81658228776528 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1701213099522 (or 1701213099516 counting only the distinct ones).

The product of its digits is 1445068800, while the sum is 75.

The spelling of 81658228776528 in words is "eighty-one trillion, six hundred fifty-eight billion, two hundred twenty-eight million, seven hundred seventy-six thousand, five hundred twenty-eight".