81947885036 has 24 divisors (see below), whose sum is σ = 145870200000. Its totient is φ = 40270978064.

The previous prime is 81947885003. The next prime is 81947885051. The reversal of 81947885036 is 63058874918.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (59).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1169315 + ... + 1237413.

It is an arithmetic number, because the mean of its divisors is an integer number (6077925000).

Almost surely, 2^81947885036 is an apocalyptic number.

It is an amenable number.

81947885036 is a deficient number, since it is larger than the sum of its proper divisors (63922314964).

81947885036 is a wasteful number, since it uses less digits than its factorization.

81947885036 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73261 (or 73259 counting only the distinct ones).

The product of its (nonzero) digits is 11612160, while the sum is 59.

The spelling of 81947885036 in words is "eighty-one billion, nine hundred forty-seven million, eight hundred eighty-five thousand, thirty-six".