20381471 has 16 divisors (see below), whose sum is σ = 23639040. Its totient is φ = 17377920.

The previous prime is 20381443. The next prime is 20381479. The reversal of 20381471 is 17418302.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20381471 is a prime.

It is a super-3 number, since 3×20381471³ (a number of 23 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20381471.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20381479) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 23186 + ... + 24048.

It is an arithmetic number, because the mean of its divisors is an integer number (1477440).

Almost surely, 2^20381471 is an apocalyptic number.

20381471 is a deficient number, since it is larger than the sum of its proper divisors (3257569).

20381471 is a wasteful number, since it uses less digits than its factorization.

20381471 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1006.

The product of its (nonzero) digits is 1344, while the sum is 26.

The square root of 20381471 is about 4514.5842554991. The cubic root of 20381471 is about 273.1566901842.

Adding to 20381471 its reverse (17418302), we get a palindrome (37799773).

The spelling of 20381471 in words is "twenty million, three hundred eighty-one thousand, four hundred seventy-one".