99971775855 has 56 divisors (see below), whose sum is σ = 205562241312. Its totient is φ = 45701371584.

The previous prime is 99971775791. The next prime is 99971775887. The reversal of 99971775855 is 55857717999.

It is not a de Polignac number, because 99971775855 - 2⁶ = 99971775791 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 55 ways as a sum of consecutive naturals, for example, 1933564 + ... + 1984593.

Almost surely, 2^99971775855 is an apocalyptic number.

99971775855 is an abundant number, since it is smaller than the sum of its proper divisors (105590465457).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

99971775855 is an equidigital number, since it uses as much as digits as its factorization.

99971775855 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3918187 (or 3918172 counting only the distinct ones).

The product of its digits is 250047000, while the sum is 72.

It can be divided in two parts, 99971 and 775855, that added together give a triangular number (875826 = T₁₃₂₃).

The spelling of 99971775855 in words is "ninety-nine billion, nine hundred seventy-one million, seven hundred seventy-five thousand, eight hundred fifty-five".