91770 has 64 divisors (see below), whose sum is σ = 276480. Its totient is φ = 19008.

The previous prime is 91757. The next prime is 91771. The reversal of 91770 is 7719.

It is an Ulam number.

It is a plaindrome in base 16.

It is a self number, because there is not a number n which added to its sum of digits gives 91770.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 91770.

It is not an unprimeable number, because it can be changed into a prime (91771) by changing a digit.

91770 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3979 + ... + 4001.

It is an arithmetic number, because the mean of its divisors is an integer number (4320).

2⁹¹⁷⁷⁰ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 91770, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (138240).

91770 is an abundant number, since it is smaller than the sum of its proper divisors (184710).

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

91770 is a wasteful number, since it uses less digits than its factorization.

91770 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59.

The product of its (nonzero) digits is 441, while the sum is 24.

The square root of 91770 is about 302.9356367283. The cubic root of 91770 is about 45.1059233161.

It can be divided in two parts, 91 and 770, that added together give a triangular number (861 = T₄₁).

The spelling of 91770 in words is "ninety-one thousand, seven hundred seventy".