99555840 has 240 divisors, whose sum is σ = 359073000. Its totient is φ = 25460736.

The previous prime is 99555821. The next prime is 99555851. The reversal of 99555840 is 4855599.

99555840 is a `hidden beast` number, since 9 + 95 + 558 + 4 + 0 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 61214976 + 38340864 = 7824^2 + 6192^2 .

It is a tau number, because it is divible by the number of its divisors (240).

It is a super-2 number, since 2×99555840² = 19822730556211200, which contains 22 as substring.

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

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 668086 + ... + 668234.

Almost surely, 2^99555840 is an apocalyptic number.

99555840 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 99555840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (179536500).

99555840 is an abundant number, since it is smaller than the sum of its proper divisors (259517160).

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

99555840 is a wasteful number, since it uses less digits than its factorization.

99555840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 207 (or 188 counting only the distinct ones).

The product of its (nonzero) digits is 324000, while the sum is 45.

The square root of 99555840 is about 9977.7672853199. The cubic root of 99555840 is about 463.4706607180.

The spelling of 99555840 in words is "ninety-nine million, five hundred fifty-five thousand, eight hundred forty".