81083644 has 6 divisors (see below), whose sum is σ = 141896384. Its totient is φ = 40541820.

The previous prime is 81083627. The next prime is 81083647. The reversal of 81083644 is 44638018.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81083647) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10135452 + ... + 10135459.

Almost surely, 2^81083644 is an apocalyptic number.

It is an amenable number.

81083644 is a deficient number, since it is larger than the sum of its proper divisors (60812740).

81083644 is a wasteful number, since it uses less digits than its factorization.

81083644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20270915 (or 20270913 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 34.

The square root of 81083644 is about 9004.6456898648. The cubic root of 81083644 is about 432.8237526014.

The spelling of 81083644 in words is "eighty-one million, eighty-three thousand, six hundred forty-four".