81735669 has 16 divisors (see below), whose sum is σ = 123077440. Its totient is φ = 53596080.

The previous prime is 81735653. The next prime is 81735713. The reversal of 81735669 is 96653718.

It is a happy number.

81735669 is a `hidden beast` number, since 81 + 7 + 3 + 566 + 9 = 666.

It is not a de Polignac number, because 81735669 - 2⁴ = 81735653 is a prime.

It is a super-2 number, since 2×81735669² = 13361439173755122, which contains 22 as substring.

It is a Duffinian number.

It is a plaindrome in base 12.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81735649) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 23167 + ... + 26460.

It is an arithmetic number, because the mean of its divisors is an integer number (7692340).

Almost surely, 2^81735669 is an apocalyptic number.

It is an amenable number.

81735669 is a deficient number, since it is larger than the sum of its proper divisors (41341771).

81735669 is a wasteful number, since it uses less digits than its factorization.

81735669 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49697 (or 49691 counting only the distinct ones).

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

The square root of 81735669 is about 9040.7781191665. The cubic root of 81735669 is about 433.9808244694.

The spelling of 81735669 in words is "eighty-one million, seven hundred thirty-five thousand, six hundred sixty-nine".