99778500 has 192 divisors, whose sum is σ = 340704000. Its totient is φ = 25142400.

The previous prime is 99778487. The next prime is 99778507. The reversal of 99778500 is 587799.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (99778507) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 256306 + ... + 256694.

It is an arithmetic number, because the mean of its divisors is an integer number (1774500).

Almost surely, 2^99778500 is an apocalyptic number.

99778500 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 99778500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (170352000).

99778500 is an abundant number, since it is smaller than the sum of its proper divisors (240925500).

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

99778500 is a wasteful number, since it uses less digits than its factorization.

99778500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 436 (or 418 counting only the distinct ones).

The product of its (nonzero) digits is 158760, while the sum is 45.

The square root of 99778500 is about 9988.9188604173. The cubic root of 99778500 is about 463.8159260441.

It can be divided in two parts, 997 and 78500, that added together give a palindrome (79497).

The spelling of 99778500 in words is "ninety-nine million, seven hundred seventy-eight thousand, five hundred".