81000564048 has 30 divisors (see below), whose sum is σ = 226689078954. Its totient is φ = 27000187968.

The previous prime is 81000563993. The next prime is 81000564049. The reversal of 81000564048 is 84046500018.

81000564048 is a `hidden beast` number, since 8 + 1 + 0 + 0 + 0 + 5 + 640 + 4 + 8 = 666.

It can be written as a sum of positive squares in only one way, i.e., 71828288064 + 9172275984 = 268008^2 + 95772^2 .

It is a super-2 number, since 2×81000564048² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81000564049) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 281251815 + ... + 281252102.

Almost surely, 2^81000564048 is an apocalyptic number.

It is an amenable number.

81000564048 is an abundant number, since it is smaller than the sum of its proper divisors (145688514906).

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

81000564048 is a wasteful number, since it uses less digits than its factorization.

81000564048 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 562503931 (or 562503922 counting only the distinct ones).

The product of its (nonzero) digits is 30720, while the sum is 36.

The spelling of 81000564048 in words is "eighty-one billion, five hundred sixty-four thousand, forty-eight".