81228657968 has 10 divisors (see below), whose sum is σ = 157380524844. Its totient is φ = 40614328976.

The previous prime is 81228657947. The next prime is 81228658079. The reversal of 81228657968 is 86975682218.

It is a self number, because there is not a number n which added to its sum of digits gives 81228657968.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2538395546 + ... + 2538395577.

Almost surely, 2^81228657968 is an apocalyptic number.

It is an amenable number.

81228657968 is a deficient number, since it is larger than the sum of its proper divisors (76151866876).

81228657968 is a wasteful number, since it uses less digits than its factorization.

81228657968 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5076791131 (or 5076791125 counting only the distinct ones).

The product of its digits is 23224320, while the sum is 62.

The spelling of 81228657968 in words is "eighty-one billion, two hundred twenty-eight million, six hundred fifty-seven thousand, nine hundred sixty-eight".