2138881 has 4 divisors (see below), whose sum is σ = 2142000. Its totient is φ = 2135764.

The previous prime is 2138879. The next prime is 2138897. The reversal of 2138881 is 1888312.

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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 2138881 - 2¹ = 2138879 is a prime.

It is a super-2 number, since 2×2138881² = 9149623864322, which contains 22 as substring.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2138831) 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, 31 + ... + 2068.

It is an arithmetic number, because the mean of its divisors is an integer number (535500).

2^2138881 is an apocalyptic number.

It is an amenable number.

2138881 is a deficient number, since it is larger than the sum of its proper divisors (3119).

2138881 is a wasteful number, since it uses less digits than its factorization.

2138881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3118.

The product of its digits is 3072, while the sum is 31.

The square root of 2138881 is about 1462.4913674959. The cubic root of 2138881 is about 128.8434091367.

The spelling of 2138881 in words is "two million, one hundred thirty-eight thousand, eight hundred eighty-one".