91821600 has 360 divisors, whose sum is σ = 363922020. Its totient is φ = 22394880.

The previous prime is 91821577. The next prime is 91821601. The reversal of 91821600 is 612819.

It can be written as a sum of positive squares in 6 ways, for example, as 25040016 + 66781584 = 5004^2 + 8172^2 .

It is a tau number, because it is divible by the number of its divisors (360).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (91821601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 842346 + ... + 842454.

Almost surely, 2^91821600 is an apocalyptic number.

91821600 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 91821600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (181961010).

91821600 is an abundant number, since it is smaller than the sum of its proper divisors (272100420).

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

91821600 is a wasteful number, since it uses less digits than its factorization.

91821600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 154 (or 132 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 27.

The square root of 91821600 is about 9582.3587910284. The cubic root of 91821600 is about 451.1437571362.

The spelling of 91821600 in words is "ninety-one million, eight hundred twenty-one thousand, six hundred".