820081928077 has 4 divisors (see below), whose sum is σ = 820470410496. Its totient is φ = 819693445660.

The previous prime is 820081928053. The next prime is 820081928137. The reversal of 820081928077 is 770829180028.

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 820081928077 - 2¹¹ = 820081926029 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 (820081928027) 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, 194238043 + ... + 194242264.

It is an arithmetic number, because the mean of its divisors is an integer number (205117602624).

Almost surely, 2^820081928077 is an apocalyptic number.

It is an amenable number.

820081928077 is a deficient number, since it is larger than the sum of its proper divisors (388482419).

820081928077 is a wasteful number, since it uses less digits than its factorization.

820081928077 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 388482418.

The product of its (nonzero) digits is 903168, while the sum is 52.

The spelling of 820081928077 in words is "eight hundred twenty billion, eighty-one million, nine hundred twenty-eight thousand, seventy-seven".