181320685 has 64 divisors (see below), whose sum is σ = 279272448. Its totient is φ = 109983744.

The previous prime is 181320677. The next prime is 181320701. The reversal of 181320685 is 586023181.

It is not a de Polignac number, because 181320685 - 2³ = 181320677 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 181320685.

It is a congruent number.

It is an unprimeable number.

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 63 ways as a sum of consecutive naturals, for example, 1760344 + ... + 1760446.

It is an arithmetic number, because the mean of its divisors is an integer number (4363632).

Almost surely, 2^181320685 is an apocalyptic number.

It is an amenable number.

181320685 is a deficient number, since it is larger than the sum of its proper divisors (97951763).

181320685 is a wasteful number, since it uses less digits than its factorization.

181320685 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 254.

The product of its (nonzero) digits is 11520, while the sum is 34.

The square root of 181320685 is about 13465.5369369365. The cubic root of 181320685 is about 565.9991561459. Note that the first 3 decimals are identical.

The spelling of 181320685 in words is "one hundred eighty-one million, three hundred twenty thousand, six hundred eighty-five".