2100381 has 4 divisors (see below), whose sum is σ = 2800512. Its totient is φ = 1400252.

The previous prime is 2100377. The next prime is 2100403. The reversal of 2100381 is 1830012.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 2100381 - 2² = 2100377 is a prime.

It is a super-2 number, since 2×2100381² = 8823200690322, which contains 22 as substring.

It is a D-number.

It is a self number, because there is not a number n which added to its sum of digits gives 2100381.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2100181) 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, 350061 + ... + 350066.

It is an arithmetic number, because the mean of its divisors is an integer number (700128).

2^2100381 is an apocalyptic number.

It is an amenable number.

2100381 is a deficient number, since it is larger than the sum of its proper divisors (700131).

2100381 is an equidigital number, since it uses as much as digits as its factorization.

2100381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 700130.

The product of its (nonzero) digits is 48, while the sum is 15.

The square root of 2100381 is about 1449.2691261460. The cubic root of 2100381 is about 128.0656604854.

Adding to 2100381 its reverse (1830012), we get a palindrome (3930393).

The spelling of 2100381 in words is "two million, one hundred thousand, three hundred eighty-one".