20381817 has 8 divisors (see below), whose sum is σ = 27314496. Its totient is φ = 13518512.

The previous prime is 20381807. The next prime is 20381821. The reversal of 20381817 is 71818302.

It is a happy number.

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 20381817 - 2⁷ = 20381689 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20381807) 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, 16653 + ... + 17834.

It is an arithmetic number, because the mean of its divisors is an integer number (3414312).

Almost surely, 2^20381817 is an apocalyptic number.

It is an amenable number.

20381817 is a deficient number, since it is larger than the sum of its proper divisors (6932679).

20381817 is a wasteful number, since it uses less digits than its factorization.

20381817 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34687.

The product of its (nonzero) digits is 2688, while the sum is 30.

The square root of 20381817 is about 4514.6225755870. The cubic root of 20381817 is about 273.1582358967.

The spelling of 20381817 in words is "twenty million, three hundred eighty-one thousand, eight hundred seventeen".