77820873564997 has 8 divisors (see below), whose sum is σ = 80545999384440. Its totient is φ = 75098524240320.

The previous prime is 77820873564989. The next prime is 77820873565007. The reversal of 77820873564997 is 79946537802877.

It is a Cunningham number, because it is equal to 8821614²+1.

It can be written as a sum of positive squares in 4 ways, for example, as 40807387220356 + 37013486344641 = 6388066^2 + 6083871^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 77820873564997 - 2³ = 77820873564989 is a prime.

It is a super-2 number, since 2×77820873564997² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 77820873564997.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77820873564197) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 694066654 + ... + 694178767.

It is an arithmetic number, because the mean of its divisors is an integer number (10068249923055).

Almost surely, 2^{77820873564997} is an apocalyptic number.

It is an amenable number.

77820873564997 is a deficient number, since it is larger than the sum of its proper divisors (2725125819443).

77820873564997 is a wasteful number, since it uses less digits than its factorization.

77820873564997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1388247383.

The product of its (nonzero) digits is 8961684480, while the sum is 82.

The spelling of 77820873564997 in words is "seventy-seven trillion, eight hundred twenty billion, eight hundred seventy-three million, five hundred sixty-four thousand, nine hundred ninety-seven".