20415381 has 8 divisors (see below), whose sum is σ = 31109184. Its totient is φ = 11665920.

The previous prime is 20415359. The next prime is 20415383. The reversal of 20415381 is 18351402.

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

It is not a de Polignac number, because 20415381 - 2⁵ = 20415349 is a prime.

It is a super-2 number, since 2×20415381² = 833575562750322, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20415383) 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, 486060 + ... + 486101.

It is an arithmetic number, because the mean of its divisors is an integer number (3888648).

Almost surely, 2^20415381 is an apocalyptic number.

20415381 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

20415381 is a deficient number, since it is larger than the sum of its proper divisors (10693803).

20415381 is an equidigital number, since it uses as much as digits as its factorization.

20415381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 972171.

The product of its (nonzero) digits is 960, while the sum is 24.

The square root of 20415381 is about 4518.3383007473. The cubic root of 20415381 is about 273.3080958587.

Adding to 20415381 its reverse (18351402), we get a palindrome (38766783).

The spelling of 20415381 in words is "twenty million, four hundred fifteen thousand, three hundred eighty-one".