81355706 has 8 divisors (see below), whose sum is σ = 123113844. Its totient is φ = 40317760.

The previous prime is 81355697. The next prime is 81355717. The reversal of 81355706 is 60755318.

It can be written as a sum of positive squares in 2 ways, for example, as 80263681 + 1092025 = 8959^2 + 1045^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 179765 + ... + 180216.

Almost surely, 2^81355706 is an apocalyptic number.

81355706 is a deficient number, since it is larger than the sum of its proper divisors (41758138).

81355706 is a wasteful number, since it uses less digits than its factorization.

81355706 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 360096.

The product of its (nonzero) digits is 25200, while the sum is 35.

The square root of 81355706 is about 9019.7397966904. The cubic root of 81355706 is about 433.3073003427.

The spelling of 81355706 in words is "eighty-one million, three hundred fifty-five thousand, seven hundred six".