396355821 has 4 divisors (see below), whose sum is σ = 528474432. Its totient is φ = 264237212.

The previous prime is 396355807. The next prime is 396355831. The reversal of 396355821 is 128553693.

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 a cyclic number.

It is not a de Polignac number, because 396355821 - 2¹⁹ = 395831533 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (396355831) 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, 66059301 + ... + 66059306.

It is an arithmetic number, because the mean of its divisors is an integer number (132118608).

Almost surely, 2^396355821 is an apocalyptic number.

It is an amenable number.

396355821 is a deficient number, since it is larger than the sum of its proper divisors (132118611).

396355821 is a wasteful number, since it uses less digits than its factorization.

396355821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 132118610.

The product of its digits is 194400, while the sum is 42.

The square root of 396355821 is about 19908.6870737374. The cubic root of 396355821 is about 734.5619250765.

The spelling of 396355821 in words is "three hundred ninety-six million, three hundred fifty-five thousand, eight hundred twenty-one".