99955213778 has 24 divisors (see below), whose sum is σ = 174422604672. Its totient is φ = 42835257864.

The previous prime is 99955213759. The next prime is 99955213793. The reversal of 99955213778 is 87731255999.

It is a happy number.

It is a super-2 number, since 2×99955213778² (a number of 23 digits) contains 22 as substring.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2876375 + ... + 2910917.

It is an arithmetic number, because the mean of its divisors is an integer number (7267608528).

Almost surely, 2^99955213778 is an apocalyptic number.

99955213778 is a gapful number since it is divisible by the number (98) formed by its first and last digit.

99955213778 is a deficient number, since it is larger than the sum of its proper divisors (74467390894).

99955213778 is a wasteful number, since it uses less digits than its factorization.

99955213778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64086 (or 64079 counting only the distinct ones).

The product of its digits is 42865200, while the sum is 65.

The spelling of 99955213778 in words is "ninety-nine billion, nine hundred fifty-five million, two hundred thirteen thousand, seven hundred seventy-eight".