978421 has 4 divisors (see below), whose sum is σ = 985600. Its totient is φ = 971244.

The previous prime is 978413. The next prime is 978427. The reversal of 978421 is 124879.

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, and also an emirpimes, since its reverse is a distinct semiprime: 124879 = 47 ⋅2657.

It is a cyclic number.

It is not a de Polignac number, because 978421 - 2³ = 978413 is a prime.

It is a Duffinian number.

978421 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (978427) 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, 3381 + ... + 3658.

It is an arithmetic number, because the mean of its divisors is an integer number (246400).

2⁹⁷⁸⁴²¹ is an apocalyptic number.

It is an amenable number.

978421 is a deficient number, since it is larger than the sum of its proper divisors (7179).

978421 is a wasteful number, since it uses less digits than its factorization.

978421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7178.

The product of its digits is 4032, while the sum is 31.

The square root of 978421 is about 989.1516567241. The cubic root of 978421 is about 99.2754631417.

The spelling of 978421 in words is "nine hundred seventy-eight thousand, four hundred twenty-one".