91163880 has 192 divisors, whose sum is σ = 313709760. Its totient is φ = 23804928.

The previous prime is 91163833. The next prime is 91163899. The reversal of 91163880 is 8836119.

91163880 is a `hidden beast` number, since 9 + 11 + 638 + 8 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 806704 + ... + 806816.

It is an arithmetic number, because the mean of its divisors is an integer number (1633905).

Almost surely, 2^91163880 is an apocalyptic number.

91163880 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 91163880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (156854880).

91163880 is an abundant number, since it is smaller than the sum of its proper divisors (222545880).

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

91163880 is a wasteful number, since it uses less digits than its factorization.

91163880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 222 (or 206 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 36.

The square root of 91163880 is about 9547.9777963713. The cubic root of 91163880 is about 450.0639908999.

Adding to 91163880 its reverse (8836119), we get a palindrome (99999999).

It can be divided in two parts, 9116 and 3880, that added together give a square (12996 = 114²).

The spelling of 91163880 in words is "ninety-one million, one hundred sixty-three thousand, eight hundred eighty".