81488861988 has 48 divisors (see below), whose sum is σ = 191072777280. Its totient is φ = 27030011904.

The previous prime is 81488861969. The next prime is 81488862001. The reversal of 81488861988 is 88916888418.

It is a super-2 number, since 2×81488861988² (a number of 23 digits) contains 22 as substring.

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 in 15 ways as a sum of consecutive naturals, for example, 3172983 + ... + 3198561.

It is an arithmetic number, because the mean of its divisors is an integer number (3980682860).

Almost surely, 2^81488861988 is an apocalyptic number.

It is an amenable number.

81488861988 is an abundant number, since it is smaller than the sum of its proper divisors (109583915292).

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

81488861988 is a wasteful number, since it uses less digits than its factorization.

81488861988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26876 (or 26874 counting only the distinct ones).

The product of its digits is 56623104, while the sum is 69.

The spelling of 81488861988 in words is "eighty-one billion, four hundred eighty-eight million, eight hundred sixty-one thousand, nine hundred eighty-eight".