91980000 has 360 divisors, whose sum is σ = 378666288. Its totient is φ = 20736000.

The previous prime is 91979999. The next prime is 91980001. The reversal of 91980000 is 8919.

It is an interprime number because it is at equal distance from previous prime (91979999) and next prime (91980001).

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

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91980001) by changing a digit.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 1259964 + ... + 1260036.

Almost surely, 2^91980000 is an apocalyptic number.

91980000 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 91980000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (189333144).

91980000 is an abundant number, since it is smaller than the sum of its proper divisors (286686288).

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

91980000 is a wasteful number, since it uses less digits than its factorization.

91980000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 116 (or 90 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 27.

The square root of 91980000 is about 9590.6204178875. The cubic root of 91980000 is about 451.4030284416.

Adding to 91980000 its reverse (8919), we get a palindrome (91988919).

The spelling of 91980000 in words is "ninety-one million, nine hundred eighty thousand".