784396421 has 4 divisors (see below), whose sum is σ = 784454112. Its totient is φ = 784338732.

The previous prime is 784396391. The next prime is 784396463. The reversal of 784396421 is 124693487.

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 a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 784396421 - 2¹⁰ = 784395397 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (784396721) 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, 4070 + ... + 39816.

It is an arithmetic number, because the mean of its divisors is an integer number (196113528).

Almost surely, 2^784396421 is an apocalyptic number.

It is an amenable number.

784396421 is a deficient number, since it is larger than the sum of its proper divisors (57691).

784396421 is a wasteful number, since it uses less digits than its factorization.

784396421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57690.

The product of its digits is 290304, while the sum is 44.

The square root of 784396421 is about 28007.0780518068. The cubic root of 784396421 is about 922.2426466603.

The spelling of 784396421 in words is "seven hundred eighty-four million, three hundred ninety-six thousand, four hundred twenty-one".