396280821 has 4 divisors (see below), whose sum is σ = 528374432. Its totient is φ = 264187212.

The previous prime is 396280811. The next prime is 396280889. The reversal of 396280821 is 128082693.

It is a happy number.

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 not a de Polignac number, because 396280821 - 2¹⁰ = 396279797 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 396280821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (396280811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 66046801 + ... + 66046806.

It is an arithmetic number, because the mean of its divisors is an integer number (132093608).

Almost surely, 2^396280821 is an apocalyptic number.

It is an amenable number.

396280821 is a deficient number, since it is larger than the sum of its proper divisors (132093611).

396280821 is a wasteful number, since it uses less digits than its factorization.

396280821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 132093610.

The product of its (nonzero) digits is 41472, while the sum is 39.

The square root of 396280821 is about 19906.8033847728. The cubic root of 396280821 is about 734.5155899261.

The spelling of 396280821 in words is "three hundred ninety-six million, two hundred eighty thousand, eight hundred twenty-one".