421978 has 8 divisors (see below), whose sum is σ = 639540. Its totient is φ = 208800.

The previous prime is 421973. The next prime is 421987. The reversal of 421978 is 879124.

It can be written as a sum of positive squares in 2 ways, for example, as 321489 + 100489 = 567^2 + 317^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (421973) 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, 843 + ... + 1246.

2⁴²¹⁹⁷⁸ is an apocalyptic number.

421978 is a deficient number, since it is larger than the sum of its proper divisors (217562).

421978 is a wasteful number, since it uses less digits than its factorization.

421978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2192.

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

The square root of 421978 is about 649.5983374363. The cubic root of 421978 is about 75.0061032070.

The spelling of 421978 in words is "four hundred twenty-one thousand, nine hundred seventy-eight".