820677156401 has 4 divisors (see below), whose sum is σ = 820714214400. Its totient is φ = 820640098404.

The previous prime is 820677156391. The next prime is 820677156421. The reversal of 820677156401 is 104651776028.

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 a de Polignac number, because none of the positive numbers 2^k-820677156401 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (820677156421) 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, 18495761 + ... + 18540078.

It is an arithmetic number, because the mean of its divisors is an integer number (205178553600).

Almost surely, 2^820677156401 is an apocalyptic number.

It is an amenable number.

820677156401 is a deficient number, since it is larger than the sum of its proper divisors (37057999).

820677156401 is a wasteful number, since it uses less digits than its factorization.

820677156401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37057998.

The product of its (nonzero) digits is 564480, while the sum is 47.

The spelling of 820677156401 in words is "eight hundred twenty billion, six hundred seventy-seven million, one hundred fifty-six thousand, four hundred one".