81695243 has 16 divisors (see below), whose sum is σ = 95585280. Its totient is φ = 68380416.

The previous prime is 81695213. The next prime is 81695279. The reversal of 81695243 is 34259618.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 81695243 - 2¹⁴ = 81678859 is a prime.

It is a super-2 number, since 2×81695243² = 13348225457658098, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 81695197 and 81695206.

It is not an unprimeable number, because it can be changed into a prime (81695213) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 52880 + ... + 54402.

It is an arithmetic number, because the mean of its divisors is an integer number (5974080).

Almost surely, 2^81695243 is an apocalyptic number.

81695243 is a deficient number, since it is larger than the sum of its proper divisors (13890037).

81695243 is a wasteful number, since it uses less digits than its factorization.

81695243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1706.

The product of its digits is 51840, while the sum is 38.

The square root of 81695243 is about 9038.5420837655. The cubic root of 81695243 is about 433.9092645159.

The spelling of 81695243 in words is "eighty-one million, six hundred ninety-five thousand, two hundred forty-three".