81443412 has 36 divisors (see below), whose sum is σ = 206344320. Its totient is φ = 27085392.

The previous prime is 81443387. The next prime is 81443429. The reversal of 81443412 is 21434418.

It is a tau number, because it is divible by the number of its divisors (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 14883 + ... + 19605.

Almost surely, 2^81443412 is an apocalyptic number.

It is an amenable number.

81443412 is an abundant number, since it is smaller than the sum of its proper divisors (124900908).

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

81443412 is a wasteful number, since it uses less digits than its factorization.

With its successor (81443413) it forms a Ruth-Aaron pair, since the sum of their distinct prime factors is the same (5207).

81443412 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5212 (or 5207 counting only the distinct ones).

The product of its digits is 3072, while the sum is 27.

The square root of 81443412 is about 9024.6003789642. The cubic root of 81443412 is about 433.4629542542.

The spelling of 81443412 in words is "eighty-one million, four hundred forty-three thousand, four hundred twelve".