820616575397 has 4 divisors (see below), whose sum is σ = 856295556960. Its totient is φ = 784937593836.

The previous prime is 820616575393. The next prime is 820616575417. The reversal of 820616575397 is 793575616028.

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 a cyclic number.

It is not a de Polignac number, because 820616575397 - 2² = 820616575393 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 (820616575391) 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, 17839490747 + ... + 17839490792.

It is an arithmetic number, because the mean of its divisors is an integer number (214073889240).

Almost surely, 2^820616575397 is an apocalyptic number.

It is an amenable number.

820616575397 is a deficient number, since it is larger than the sum of its proper divisors (35678981563).

820616575397 is a wasteful number, since it uses less digits than its factorization.

820616575397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35678981562.

The product of its (nonzero) digits is 19051200, while the sum is 59.

The spelling of 820616575397 in words is "eight hundred twenty billion, six hundred sixteen million, five hundred seventy-five thousand, three hundred ninety-seven".