81889433020 has 12 divisors (see below), whose sum is σ = 171967809384. Its totient is φ = 32755773200.

The previous prime is 81889433009. The next prime is 81889433033. The reversal of 81889433020 is 2033498818.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2047235806 + ... + 2047235845.

It is an arithmetic number, because the mean of its divisors is an integer number (14330650782).

Almost surely, 2^81889433020 is an apocalyptic number.

It is an amenable number.

81889433020 is an abundant number, since it is smaller than the sum of its proper divisors (90078376364).

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

81889433020 is a wasteful number, since it uses less digits than its factorization.

81889433020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4094471660 (or 4094471658 counting only the distinct ones).

The product of its (nonzero) digits is 331776, while the sum is 46.

The spelling of 81889433020 in words is "eighty-one billion, eight hundred eighty-nine million, four hundred thirty-three thousand, twenty".