91813370220 has 864 divisors, whose sum is σ = 348079140864. Its totient is φ = 19390924800.

The previous prime is 91813370197. The next prime is 91813370239. The reversal of 91813370220 is 2207331819.

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

It is an unprimeable number.

It is a polite number, since it can be written in 287 ways as a sum of consecutive naturals, for example, 549780577 + ... + 549780743.

It is an arithmetic number, because the mean of its divisors is an integer number (402869376).

Almost surely, 2^91813370220 is an apocalyptic number.

91813370220 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 91813370220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (174039570432).

91813370220 is an abundant number, since it is smaller than the sum of its proper divisors (256265770644).

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

91813370220 is a wasteful number, since it uses less digits than its factorization.

91813370220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 303 (or 285 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 36.

The spelling of 91813370220 in words is "ninety-one billion, eight hundred thirteen million, three hundred seventy thousand, two hundred twenty".