20650381 has 2 divisors, whose sum is σ = 20650382. Its totient is φ = 20650380.

The previous prime is 20650379. The next prime is 20650387. The reversal of 20650381 is 18305602.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19660356 + 990025 = 4434^2 + 995^2 .

It is a cyclic number.

It is not a de Polignac number, because 20650381 - 2¹ = 20650379 is a prime.

It is a super-2 number, since 2×20650381² = 852876470890322, which contains 22 as substring.

Together with 20650379, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20650387) 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 as a sum of consecutive naturals, namely, 10325190 + 10325191.

It is an arithmetic number, because the mean of its divisors is an integer number (10325191).

Almost surely, 2^20650381 is an apocalyptic number.

It is an amenable number.

20650381 is a deficient number, since it is larger than the sum of its proper divisors (1).

20650381 is an equidigital number, since it uses as much as digits as its factorization.

20650381 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 20650381 is about 4544.2690281276. The cubic root of 20650381 is about 274.3527743372.

Adding to 20650381 its reverse (18305602), we get a palindrome (38955983).

The spelling of 20650381 in words is "twenty million, six hundred fifty thousand, three hundred eighty-one".