20841681 has 8 divisors (see below), whose sum is σ = 31758784. Its totient is φ = 11909520.

The previous prime is 20841679. The next prime is 20841683. The reversal of 20841681 is 18614802.

It is an interprime number because it is at equal distance from previous prime (20841679) and next prime (20841683).

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

It is not a de Polignac number, because 20841681 - 2¹ = 20841679 is a prime.

It is a super-2 number, since 2×20841681² = 868751333811522, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20841683) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 496210 + ... + 496251.

It is an arithmetic number, because the mean of its divisors is an integer number (3969848).

Almost surely, 2^20841681 is an apocalyptic number.

20841681 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

20841681 is a deficient number, since it is larger than the sum of its proper divisors (10917103).

20841681 is an equidigital number, since it uses as much as digits as its factorization.

20841681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 992471.

The product of its (nonzero) digits is 3072, while the sum is 30.

The square root of 20841681 is about 4565.2689953605. The cubic root of 20841681 is about 275.1973503511.

The spelling of 20841681 in words is "twenty million, eight hundred forty-one thousand, six hundred eighty-one".