821678860801 has 4 divisors (see below), whose sum is σ = 821692817712. Its totient is φ = 821664903892.

The previous prime is 821678860787. The next prime is 821678860817. The reversal of 821678860801 is 108068876128.

It is a happy number.

821678860801 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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-821678860801 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (821678864801) 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, 6889771 + ... + 7008016.

It is an arithmetic number, because the mean of its divisors is an integer number (205423204428).

Almost surely, 2^821678860801 is an apocalyptic number.

It is an amenable number.

821678860801 is a deficient number, since it is larger than the sum of its proper divisors (13956911).

821678860801 is a wasteful number, since it uses less digits than its factorization.

821678860801 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13956910.

The product of its (nonzero) digits is 2064384, while the sum is 55.

The spelling of 821678860801 in words is "eight hundred twenty-one billion, six hundred seventy-eight million, eight hundred sixty thousand, eight hundred one".