842921 has 4 divisors (see below), whose sum is σ = 870144. Its totient is φ = 815700.

The previous prime is 842887. The next prime is 842923. The reversal of 842921 is 129248.

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 842921 - 2⁶ = 842857 is a prime.

It is a Duffinian number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 842921.

It is not an unprimeable number, because it can be changed into a prime (842923) 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, 13565 + ... + 13626.

It is an arithmetic number, because the mean of its divisors is an integer number (217536).

2⁸⁴²⁹²¹ is an apocalyptic number.

It is an amenable number.

842921 is a deficient number, since it is larger than the sum of its proper divisors (27223).

842921 is a wasteful number, since it uses less digits than its factorization.

842921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27222.

The product of its digits is 1152, while the sum is 26.

The square root of 842921 is about 918.1072922050. The cubic root of 842921 is about 94.4631212070.

The spelling of 842921 in words is "eight hundred forty-two thousand, nine hundred twenty-one".