91200000 has 240 divisors, whose sum is σ = 319667040. Its totient is φ = 23040000.

The previous prime is 91199993. The next prime is 91200007. The reversal of 91200000 is 219.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (91199993) and next prime (91200007).

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

It is a Harshad number since it is a multiple of its sum of digits (12).

It is not an unprimeable number, because it can be changed into a prime (91200007) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4799991 + ... + 4800009.

It is an arithmetic number, because the mean of its divisors is an integer number (1331946).

Almost surely, 2^91200000 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 91200000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (159833520).

91200000 is an abundant number, since it is smaller than the sum of its proper divisors (228467040).

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

91200000 is an frugal number, since it uses more digits than its factorization.

91200000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65 (or 29 counting only the distinct ones).

The product of its (nonzero) digits is 18, while the sum is 12.

The square root of 91200000 is about 9549.8691090507. The cubic root of 91200000 is about 450.1234229354.

Adding to 91200000 its reverse (219), we get a palindrome (91200219).

The spelling of 91200000 in words is "ninety-one million, two hundred thousand".