396821865 has 32 divisors (see below), whose sum is σ = 705718656. Its totient is φ = 188764160.

The previous prime is 396821863. The next prime is 396821879. The reversal of 396821865 is 568128693.

It is a happy number.

It is not a de Polignac number, because 396821865 - 2¹ = 396821863 is a prime.

It is not an unprimeable number, because it can be changed into a prime (396821861) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 13944 + ... + 31433.

It is an arithmetic number, because the mean of its divisors is an integer number (22053708).

Almost surely, 2^396821865 is an apocalyptic number.

It is an amenable number.

396821865 is a deficient number, since it is larger than the sum of its proper divisors (308896791).

396821865 is a wasteful number, since it uses less digits than its factorization.

396821865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45449.

The product of its digits is 622080, while the sum is 48.

The square root of 396821865 is about 19920.3881739287. The cubic root of 396821865 is about 734.8497170645.

The spelling of 396821865 in words is "three hundred ninety-six million, eight hundred twenty-one thousand, eight hundred sixty-five".