2116381 has 4 divisors (see below), whose sum is σ = 2240892. Its totient is φ = 1991872.

The previous prime is 2116357. The next prime is 2116393. The reversal of 2116381 is 1836112.

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 1322500 + 793881 = 1150^2 + 891^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2116381 is a prime.

It is a super-2 number, since 2×2116381² = 8958137074322, which contains 22 as substring.

It is a Duffinian number.

2116381 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2116351) 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, 62230 + ... + 62263.

It is an arithmetic number, because the mean of its divisors is an integer number (560223).

2^2116381 is an apocalyptic number.

It is an amenable number.

2116381 is a deficient number, since it is larger than the sum of its proper divisors (124511).

2116381 is a wasteful number, since it uses less digits than its factorization.

2116381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 124510.

The product of its digits is 288, while the sum is 22.

The square root of 2116381 is about 1454.7786773252. The cubic root of 2116381 is about 128.3900253636.

The spelling of 2116381 in words is "two million, one hundred sixteen thousand, three hundred eighty-one".