99556656677 has 4 divisors (see below), whose sum is σ = 99711971916. Its totient is φ = 99401341440.

The previous prime is 99556656649. The next prime is 99556656791. The reversal of 99556656677 is 77665665599.

It is a Cunningham number, because it is equal to 315526²+1.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 89864451076 + 9692205601 = 299774^2 + 98449^2 .

It is a cyclic number.

It is not a de Polignac number, because 99556656677 - 2²⁰ = 99555608101 is a prime.

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 99556656677.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (99556626677) 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, 77656658 + ... + 77657939.

It is an arithmetic number, because the mean of its divisors is an integer number (24927992979).

Almost surely, 2^99556656677 is an apocalyptic number.

It is an amenable number.

99556656677 is a deficient number, since it is larger than the sum of its proper divisors (155315239).

99556656677 is a wasteful number, since it uses less digits than its factorization.

99556656677 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 155315238.

The product of its digits is 642978000, while the sum is 71.

The spelling of 99556656677 in words is "ninety-nine billion, five hundred fifty-six million, six hundred fifty-six thousand, six hundred seventy-seven".