396387218509 has 4 divisors (see below), whose sum is σ = 396620526400. Its totient is φ = 396153910620.

The previous prime is 396387218449. The next prime is 396387218567. The reversal of 396387218509 is 905812783693.

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 an emirpimes, since its reverse is a distinct semiprime: 905812783693 = 47 ⋅19272612419.

It is a cyclic number.

It is not a de Polignac number, because 396387218509 - 2²¹ = 396385121357 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (396387218569) 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, 116651397 + ... + 116654794.

It is an arithmetic number, because the mean of its divisors is an integer number (99155131600).

Almost surely, 2^396387218509 is an apocalyptic number.

It is an amenable number.

396387218509 is a deficient number, since it is larger than the sum of its proper divisors (233307891).

396387218509 is a wasteful number, since it uses less digits than its factorization.

396387218509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 233307890.

The product of its (nonzero) digits is 19595520, while the sum is 61.

The spelling of 396387218509 in words is "three hundred ninety-six billion, three hundred eighty-seven million, two hundred eighteen thousand, five hundred nine".