91219968 has 216 divisors, whose sum is σ = 309508290. Its totient is φ = 25804800.

The previous prime is 91219951. The next prime is 91219979. The reversal of 91219968 is 86991219.

It can be written as a sum of positive squares in only one way, i.e., 54641664 + 36578304 = 7392^2 + 6048^2 .

It is a nude number because it is divisible by every one of its digits.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 903118 + ... + 903218.

Almost surely, 2^91219968 is an apocalyptic number.

91219968 is a gapful number since it is divisible by the number (98) 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 91219968, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (154754145).

91219968 is an abundant number, since it is smaller than the sum of its proper divisors (218288322).

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

91219968 is a wasteful number, since it uses less digits than its factorization.

91219968 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 143 (or 113 counting only the distinct ones).

The product of its digits is 69984, while the sum is 45.

The square root of 91219968 is about 9550.9145111869. The cubic root of 91219968 is about 450.1562716511.

The spelling of 91219968 in words is "ninety-one million, two hundred nineteen thousand, nine hundred sixty-eight".