81547950768 has 40 divisors (see below), whose sum is σ = 213551377968. Its totient is φ = 26810284032.

The previous prime is 81547950761. The next prime is 81547950791. The reversal of 81547950768 is 86705974518.

It is not an unprimeable number, because it can be changed into a prime (81547950761) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11632905 + ... + 11639912.

Almost surely, 2^81547950768 is an apocalyptic number.

It is an amenable number.

81547950768 is an abundant number, since it is smaller than the sum of its proper divisors (132003427200).

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

81547950768 is a wasteful number, since it uses less digits than its factorization.

81547950768 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23272901 (or 23272895 counting only the distinct ones).

The product of its (nonzero) digits is 16934400, while the sum is 60.

The spelling of 81547950768 in words is "eighty-one billion, five hundred forty-seven million, nine hundred fifty thousand, seven hundred sixty-eight".