1388921 has 4 divisors (see below), whose sum is σ = 1391952. Its totient is φ = 1385892.

The previous prime is 1388887. The next prime is 1388927. The reversal of 1388921 is 1298831.

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 1388921 - 2¹⁴ = 1372537 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1388927) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 671 + ... + 1796.

It is an arithmetic number, because the mean of its divisors is an integer number (347988).

2^1388921 is an apocalyptic number.

It is an amenable number.

1388921 is a deficient number, since it is larger than the sum of its proper divisors (3031).

1388921 is an equidigital number, since it uses as much as digits as its factorization.

1388921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3030.

The product of its digits is 3456, while the sum is 32.

The square root of 1388921 is about 1178.5249254895. The cubic root of 1388921 is about 111.5730181898.

The spelling of 1388921 in words is "one million, three hundred eighty-eight thousand, nine hundred twenty-one".