2101381 has 6 divisors (see below), whose sum is σ = 2218182. Its totient is φ = 1990440.

The previous prime is 2101357. The next prime is 2101391. The reversal of 2101381 is 1831012.

It can be written as a sum of positive squares in only one way, i.e., 2030625 + 70756 = 1425^2 + 266^2 .

It is not a de Polignac number, because 2101381 - 2⁹ = 2100869 is a prime.

It is a super-2 number, since 2×2101381² = 8831604214322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2101391) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2550 + ... + 3271.

It is an arithmetic number, because the mean of its divisors is an integer number (369697).

2^2101381 is an apocalyptic number.

It is an amenable number.

2101381 is a deficient number, since it is larger than the sum of its proper divisors (116801).

2101381 is an equidigital number, since it uses as much as digits as its factorization.

2101381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5859 (or 5840 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 16.

The square root of 2101381 is about 1449.6140865761. The cubic root of 2101381 is about 128.0859814560.

Adding to 2101381 its reverse (1831012), we get a palindrome (3932393).

The spelling of 2101381 in words is "two million, one hundred one thousand, three hundred eighty-one".