20210381 has 4 divisors (see below), whose sum is σ = 20315292. Its totient is φ = 20105472.

The previous prime is 20210369. The next prime is 20210383. The reversal of 20210381 is 18301202.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 3062500 + 17147881 = 1750^2 + 4141^2 .

It is a cyclic number.

It is not a de Polignac number, because 20210381 - 2⁶ = 20210317 is a prime.

It is a super-2 number, since 2×20210381² = 816919000330322, 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 (20210383) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 52166 + ... + 52551.

It is an arithmetic number, because the mean of its divisors is an integer number (5078823).

Almost surely, 2^20210381 is an apocalyptic number.

It is an amenable number.

20210381 is a deficient number, since it is larger than the sum of its proper divisors (104911).

20210381 is a wasteful number, since it uses less digits than its factorization.

20210381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 104910.

The product of its (nonzero) digits is 96, while the sum is 17.

The square root of 20210381 is about 4495.5957336042. The cubic root of 20210381 is about 272.3902136092.

Adding to 20210381 its reverse (18301202), we get a palindrome (38511583).

The spelling of 20210381 in words is "twenty million, two hundred ten thousand, three hundred eighty-one".