921439 has 4 divisors (see below), whose sum is σ = 927256. Its totient is φ = 915624.

The previous prime is 921409. The next prime is 921457. The reversal of 921439 is 934129.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 934129 = 7 ⋅133447.

It is a cyclic number.

It is not a de Polignac number, because 921439 - 2⁵ = 921407 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (921409) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2664 + ... + 2989.

It is an arithmetic number, because the mean of its divisors is an integer number (231814).

2⁹²¹⁴³⁹ is an apocalyptic number.

921439 is a deficient number, since it is larger than the sum of its proper divisors (5817).

921439 is a wasteful number, since it uses less digits than its factorization.

921439 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5816.

The product of its digits is 1944, while the sum is 28.

The square root of 921439 is about 959.9161421708. The cubic root of 921439 is about 97.3095647327.

The spelling of 921439 in words is "nine hundred twenty-one thousand, four hundred thirty-nine".