81808059 has 32 divisors (see below), whose sum is σ = 115974144. Its totient is φ = 51236640.

The previous prime is 81808057. The next prime is 81808061. The reversal of 81808059 is 95080818.

It is an interprime number because it is at equal distance from previous prime (81808057) and next prime (81808061).

It is not a de Polignac number, because 81808059 - 2¹ = 81808057 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81808057) 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 31 ways as a sum of consecutive naturals, for example, 624424 + ... + 624554.

It is an arithmetic number, because the mean of its divisors is an integer number (3624192).

Almost surely, 2^81808059 is an apocalyptic number.

81808059 is a deficient number, since it is larger than the sum of its proper divisors (34166085).

81808059 is a wasteful number, since it uses less digits than its factorization.

81808059 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 327.

The product of its (nonzero) digits is 23040, while the sum is 39.

The square root of 81808059 is about 9044.7807601954. The cubic root of 81808059 is about 434.1089064611.

The spelling of 81808059 in words is "eighty-one million, eight hundred eight thousand, fifty-nine".