81806624832 has 56 divisors (see below), whose sum is σ = 216468626752. Its totient is φ = 27266112000.

The previous prime is 81806624803. The next prime is 81806624839. The reversal of 81806624832 is 23842660818.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is not an unprimeable number, because it can be changed into a prime (81806624839) 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, 2918082 + ... + 2945982.

It is an arithmetic number, because the mean of its divisors is an integer number (3865511192).

Almost surely, 2^81806624832 is an apocalyptic number.

It is an amenable number.

81806624832 is an abundant number, since it is smaller than the sum of its proper divisors (134662001920).

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

81806624832 is a wasteful number, since it uses less digits than its factorization.

81806624832 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43187 (or 43177 counting only the distinct ones).

The product of its (nonzero) digits is 884736, while the sum is 48.

The spelling of 81806624832 in words is "eighty-one billion, eight hundred six million, six hundred twenty-four thousand, eight hundred thirty-two".