81695673 has 6 divisors (see below), whose sum is σ = 118004874. Its totient is φ = 54463776.

The previous prime is 81695651. The next prime is 81695683. The reversal of 81695673 is 37659618.

It is a happy number.

81695673 is a `hidden beast` number, since 81 + 6 + 9 + 567 + 3 = 666.

It can be written as a sum of positive squares in only one way, i.e., 68757264 + 12938409 = 8292^2 + 3597^2 .

It is not a de Polignac number, because 81695673 - 2⁵ = 81695641 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81695683) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4538640 + ... + 4538657.

It is an arithmetic number, because the mean of its divisors is an integer number (19667479).

Almost surely, 2^81695673 is an apocalyptic number.

It is an amenable number.

81695673 is a deficient number, since it is larger than the sum of its proper divisors (36309201).

81695673 is a wasteful number, since it uses less digits than its factorization.

81695673 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9077303 (or 9077300 counting only the distinct ones).

The product of its digits is 272160, while the sum is 45.

The square root of 81695673 is about 9038.5658707563. The cubic root of 81695673 is about 433.9100258032.

The spelling of 81695673 in words is "eighty-one million, six hundred ninety-five thousand, six hundred seventy-three".