20868381 has 8 divisors (see below), whose sum is σ = 30916160. Its totient is φ = 13912236.

The previous prime is 20868361. The next prime is 20868389. The reversal of 20868381 is 18386802.

It is not a de Polignac number, because 20868381 - 2¹⁸ = 20606237 is a prime.

It is a super-2 number, since 2×20868381² = 870978651122322, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20868389) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 386425 + ... + 386478.

It is an arithmetic number, because the mean of its divisors is an integer number (3864520).

Almost surely, 2^20868381 is an apocalyptic number.

It is an amenable number.

20868381 is a deficient number, since it is larger than the sum of its proper divisors (10047779).

20868381 is an equidigital number, since it uses as much as digits as its factorization.

20868381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 772912 (or 772906 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 36.

The square root of 20868381 is about 4568.1923120639. The cubic root of 20868381 is about 275.3148174239.

The spelling of 20868381 in words is "twenty million, eight hundred sixty-eight thousand, three hundred eighty-one".