20256181 has 8 divisors (see below), whose sum is σ = 22860000. Its totient is φ = 17779440.

The previous prime is 20256161. The next prime is 20256217. The reversal of 20256181 is 18165202.

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 20256181 - 2⁵ = 20256149 is a prime.

It is a super-2 number, since 2×20256181² = 820625737409522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20256151) 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 7 ways as a sum of consecutive naturals, for example, 31431 + ... + 32068.

It is an arithmetic number, because the mean of its divisors is an integer number (2857500).

Almost surely, 2^20256181 is an apocalyptic number.

It is an amenable number.

20256181 is a deficient number, since it is larger than the sum of its proper divisors (2603819).

20256181 is a wasteful number, since it uses less digits than its factorization.

20256181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63539.

The product of its (nonzero) digits is 960, while the sum is 25.

The square root of 20256181 is about 4500.6867253787. The cubic root of 20256181 is about 272.5958185046.

The spelling of 20256181 in words is "twenty million, two hundred fifty-six thousand, one hundred eighty-one".