81475807 has 8 divisors (see below), whose sum is σ = 93340800. Its totient is φ = 69667224.

The previous prime is 81475799. The next prime is 81475853. The reversal of 81475807 is 70857418.

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

It is a cyclic number.

It is not a de Polignac number, because 81475807 - 2³ = 81475799 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81475807.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81475507) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10957 + ... + 16822.

It is an arithmetic number, because the mean of its divisors is an integer number (11667600).

Almost surely, 2^81475807 is an apocalyptic number.

81475807 is a deficient number, since it is larger than the sum of its proper divisors (11864993).

81475807 is a wasteful number, since it uses less digits than its factorization.

81475807 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28205.

The product of its (nonzero) digits is 62720, while the sum is 40.

The square root of 81475807 is about 9026.3950168381. The cubic root of 81475807 is about 433.5204181655.

The spelling of 81475807 in words is "eighty-one million, four hundred seventy-five thousand, eight hundred seven".