2138391 has 12 divisors (see below), whose sum is σ = 3147768. Its totient is φ = 1398384.

The previous prime is 2138387. The next prime is 2138399. The reversal of 2138391 is 1938312.

It is not a de Polignac number, because 2138391 - 2² = 2138387 is a prime.

2138391 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2138399) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1765 + ... + 2718.

It is an arithmetic number, because the mean of its divisors is an integer number (262314).

2^2138391 is an apocalyptic number.

2138391 is a deficient number, since it is larger than the sum of its proper divisors (1009377).

2138391 is a wasteful number, since it uses less digits than its factorization.

2138391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4542 (or 4539 counting only the distinct ones).

The product of its digits is 1296, while the sum is 27.

The square root of 2138391 is about 1462.3238355440. The cubic root of 2138391 is about 128.8335693977.

The spelling of 2138391 in words is "two million, one hundred thirty-eight thousand, three hundred ninety-one".