77744249855 has 4 divisors (see below), whose sum is σ = 93293099832. Its totient is φ = 62195399880.

The previous prime is 77744249851. The next prime is 77744249879. The reversal of 77744249855 is 55894244777.

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

It is not a de Polignac number, because 77744249855 - 2² = 77744249851 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 (77744249851) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7774424981 + ... + 7774424990.

It is an arithmetic number, because the mean of its divisors is an integer number (23323274958).

Almost surely, 2^77744249855 is an apocalyptic number.

77744249855 is a deficient number, since it is larger than the sum of its proper divisors (15548849977).

77744249855 is a wasteful number, since it uses less digits than its factorization.

77744249855 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15548849976.

The product of its digits is 79027200, while the sum is 62.

The spelling of 77744249855 in words is "seventy-seven billion, seven hundred forty-four million, two hundred forty-nine thousand, eight hundred fifty-five".