8216778977 has 4 divisors (see below), whose sum is σ = 8963758896. Its totient is φ = 7469799060.

The previous prime is 8216778967. The next prime is 8216778991. The reversal of 8216778977 is 7798776128.

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 8216778977 - 2¹⁶ = 8216713441 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (8216778907) 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, 373489943 + ... + 373489964.

It is an arithmetic number, because the mean of its divisors is an integer number (2240939724).

Almost surely, 2^8216778977 is an apocalyptic number.

It is an amenable number.

8216778977 is a deficient number, since it is larger than the sum of its proper divisors (746979919).

8216778977 is a wasteful number, since it uses less digits than its factorization.

8216778977 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 746979918.

The product of its digits is 16595712, while the sum is 62.

The square root of 8216778977 is about 90646.4504379515. The cubic root of 8216778977 is about 2017.9041570521.

The spelling of 8216778977 in words is "eight billion, two hundred sixteen million, seven hundred seventy-eight thousand, nine hundred seventy-seven".