421779 has 4 divisors (see below), whose sum is σ = 562376. Its totient is φ = 281184.

The previous prime is 421741. The next prime is 421783. The reversal of 421779 is 977124.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 421779 - 2¹³ = 413587 is a prime.

It is a D-number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (421709) 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, 70294 + ... + 70299.

It is an arithmetic number, because the mean of its divisors is an integer number (140594).

2⁴²¹⁷⁷⁹ is an apocalyptic number.

421779 is a deficient number, since it is larger than the sum of its proper divisors (140597).

421779 is a wasteful number, since it uses less digits than its factorization.

421779 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 140596.

The product of its digits is 3528, while the sum is 30.

The square root of 421779 is about 649.4451477993. The cubic root of 421779 is about 74.9943106795.

The spelling of 421779 in words is "four hundred twenty-one thousand, seven hundred seventy-nine".