91199969280 has 384 divisors, whose sum is σ = 370507737600. Its totient is φ = 20845264896.

The previous prime is 91199969279. The next prime is 91199969281. The reversal of 91199969280 is 8296999119.

It is an interprime number because it is at equal distance from previous prime (91199969279) and next prime (91199969281).

It is a tau number, because it is divible by the number of its divisors (384).

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91199969281) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1911799 + ... + 1958921.

It is an arithmetic number, because the mean of its divisors is an integer number (964863900).

Almost surely, 2^91199969280 is an apocalyptic number.

91199969280 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 91199969280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (185253868800).

91199969280 is an abundant number, since it is smaller than the sum of its proper divisors (279307768320).

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

91199969280 is a wasteful number, since it uses less digits than its factorization.

91199969280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47166 (or 47140 counting only the distinct ones).

The product of its (nonzero) digits is 5668704, while the sum is 63.

The spelling of 91199969280 in words is "ninety-one billion, one hundred ninety-nine million, nine hundred sixty-nine thousand, two hundred eighty".