1138921 has 4 divisors (see below), whose sum is σ = 1301632. Its totient is φ = 976212.

The previous prime is 1138919. The next prime is 1138957. The reversal of 1138921 is 1298311.

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 1138921 - 2¹ = 1138919 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1138901) 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, 81345 + ... + 81358.

It is an arithmetic number, because the mean of its divisors is an integer number (325408).

2^1138921 is an apocalyptic number.

It is an amenable number.

1138921 is a deficient number, since it is larger than the sum of its proper divisors (162711).

1138921 is an equidigital number, since it uses as much as digits as its factorization.

1138921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 162710.

The product of its digits is 432, while the sum is 25.

The square root of 1138921 is about 1067.2024175385. The cubic root of 1138921 is about 104.4314240681.

Subtracting from 1138921 its product of digits (432), we obtain a square (1138489 = 1067²).

The spelling of 1138921 in words is "one million, one hundred thirty-eight thousand, nine hundred twenty-one".