81683073 has 10 divisors (see below), whose sum is σ = 122020514. Its totient is φ = 54455328.

The previous prime is 81683057. The next prime is 81683083. The reversal of 81683073 is 37038618.

It can be written as a sum of positive squares in only one way, i.e., 47775744 + 33907329 = 6912^2 + 5823^2 .

It is not a de Polignac number, because 81683073 - 2⁴ = 81683057 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81683003) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 504136 + ... + 504297.

Almost surely, 2^81683073 is an apocalyptic number.

It is an amenable number.

81683073 is a deficient number, since it is larger than the sum of its proper divisors (40337441).

81683073 is a wasteful number, since it uses less digits than its factorization.

81683073 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1008445 (or 1008436 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 36.

The square root of 81683073 is about 9037.8688306481. The cubic root of 81683073 is about 433.8877172067.

The spelling of 81683073 in words is "eighty-one million, six hundred eighty-three thousand, seventy-three".